<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
is	O
the	O
first	O
major	O
release	O
of	O
the	O
Windows	B-Device
NT	I-Device
operating	B-General_Concept
system	I-General_Concept
developed	O
by	O
Microsoft	O
,	O
released	O
on	O
July	O
27	O
,	O
1993	O
.	O
</s>
<s>
At	O
the	O
time	O
of	O
Windows	B-Device
NT	I-Device
's	O
release	O
,	O
Microsoft	O
's	O
Windows	B-Application
3.1	I-Application
desktop	O
environment	O
had	O
established	O
brand	O
recognition	O
and	O
market	O
share	O
;	O
but	O
Windows	B-Application
3.1	I-Application
relied	O
on	O
the	O
DOS	B-Device
operating	B-General_Concept
system	I-General_Concept
for	O
essential	O
functions	O
,	O
and	O
it	O
had	O
a	O
constrictive	O
16-bit	B-Device
architecture	I-Device
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
,	O
however	O
,	O
was	O
a	O
complete	O
,	O
32-bit	O
operating	B-General_Concept
system	I-General_Concept
that	O
retained	O
a	O
desktop	O
environment	O
familiar	O
to	O
Windows	B-Application
3.1	I-Application
users	O
.	O
</s>
<s>
By	O
extending	O
the	O
Windows	B-Application
brand	O
and	O
beginning	O
Windows	B-Device
NT	I-Device
at	O
version	O
3.1	O
,	O
Microsoft	O
implied	O
that	O
consumers	O
should	O
expect	O
a	O
familiar	O
user	B-Application
experience	I-Application
.	O
</s>
<s>
The	O
name	O
Windows	B-Device
NT	I-Device
(	O
"	O
New	O
Technology	O
"	O
)	O
advertised	O
that	O
this	O
was	O
a	O
re-engineered	O
version	O
of	O
Windows	B-Application
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
began	O
as	O
a	O
rewrite	O
of	O
the	O
OS/2	B-Application
operating	B-General_Concept
system	I-General_Concept
,	O
which	O
Microsoft	O
had	O
co-developed	O
with	O
IBM	O
in	O
the	O
1980s	O
.	O
</s>
<s>
For	O
several	O
reasons	O
,	O
including	O
the	O
market	O
success	O
of	O
Windows	B-Application
3.0	I-Application
in	O
1990	O
,	O
Microsoft	O
decided	O
to	O
advance	O
Windows	B-Application
rather	O
than	O
OS/2	B-Application
.	O
</s>
<s>
They	O
relinquished	O
their	O
OS/2	B-Application
development	O
responsibilities	O
to	O
IBM	O
,	O
and	O
forked	B-Application
their	O
work	O
on	O
OS/2	B-Application
v3.0	O
into	O
a	O
competing	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
sold	O
about	O
300,000	O
copies	O
before	O
it	O
was	O
succeeded	O
by	O
Windows	B-Device
NT	I-Device
3.5	I-Device
in	O
1994	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
was	O
available	O
in	O
two	O
editions	O
:	O
Windows	B-Device
NT	I-Device
3.1	I-Device
for	O
workstations	B-Device
,	O
and	O
Windows	B-Device
NT	I-Device
3.1	I-Device
Advanced	O
Server	O
for	O
servers	B-Application
.	O
</s>
<s>
When	O
these	O
premiered	O
,	O
their	O
sales	O
were	O
limited	O
by	O
high	O
system	O
requirements	O
,	O
and	O
a	O
general	O
lack	O
of	O
32-bit	O
applications	B-Application
to	O
take	O
advantage	O
of	O
the	O
OS	O
's	O
data	O
processing	O
capabilities	O
.	O
</s>
<s>
On	O
December	O
31	O
,	O
2000	O
,	O
Microsoft	O
declared	O
Windows	B-Device
NT	I-Device
3.1	I-Device
obsolete	O
and	O
stopped	O
providing	O
support	O
and	O
updates	O
for	O
the	O
system	O
.	O
</s>
<s>
The	O
origins	O
of	O
Windows	B-Device
NT	I-Device
date	O
back	O
to	O
1988	O
,	O
where	O
Microsoft	O
had	O
a	O
major	O
foothold	O
on	O
the	O
personal	B-Device
computer	I-Device
market	O
due	O
to	O
the	O
use	O
of	O
its	O
MS-DOS	B-Application
as	O
the	O
operating	B-General_Concept
system	I-General_Concept
of	O
IBM	O
PC	O
compatibles	O
.	O
</s>
<s>
Nathan	O
Myhrvold	O
,	O
who	O
had	O
joined	O
Microsoft	O
after	O
its	O
acquisition	O
of	O
Dynamical	O
Systems	O
Research	O
,	O
identified	O
two	O
major	O
threats	O
to	O
Microsoft	O
's	O
monopoly	O
—	O
RISC	B-Architecture
architectures	I-Architecture
,	O
which	O
proved	O
to	O
be	O
more	O
powerful	O
than	O
the	O
equivalent	O
Intel	O
processors	O
that	O
MS-DOS	B-Application
ran	O
on	O
,	O
and	O
Unix	B-Application
,	O
a	O
family	O
of	O
cross-platform	B-Operating_System
multitasking	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
with	O
support	O
for	O
multiprocessing	B-Operating_System
and	O
networking	B-Architecture
.	O
</s>
<s>
While	O
the	O
widespread	O
use	O
of	O
Unix	B-Application
was	O
hindered	O
by	O
the	O
need	O
to	O
adapt	O
programs	O
for	O
each	O
individual	O
variant	O
,	O
Bill	O
Gates	O
believed	O
that	O
the	O
combination	O
of	O
a	O
Unix-like	O
operating	B-General_Concept
system	I-General_Concept
with	O
RISC	B-Architecture
processors	I-Architecture
could	O
be	O
a	O
market	O
threat	O
,	O
prompting	O
the	O
need	O
for	O
Microsoft	O
to	O
develop	O
a	O
"	O
Unix	B-Application
killer	O
"	O
that	O
could	O
run	O
on	O
multiple	O
architectures	O
.	O
</s>
<s>
Myhrvold	O
wanted	O
to	O
develop	O
a	O
new	O
system	O
that	O
would	O
run	O
on	O
RISC	B-Architecture
workstations	B-Device
and	O
Intel	O
chips	O
and	O
multiprocessing	B-Operating_System
computers	O
.	O
</s>
<s>
Gates	O
had	O
also	O
hired	O
Dave	O
Cutler	O
from	O
Digital	O
Equipment	O
Corporation	O
to	O
assist	O
in	O
developing	O
the	O
new	O
operating	B-General_Concept
system	I-General_Concept
;	O
Cutler	O
left	O
DEC	O
after	O
a	O
series	O
of	O
conflicts	O
surrounding	O
its	O
work	O
on	O
the	O
PRISM	B-Architecture
architecture	O
and	O
its	O
MICA	B-Operating_System
operating	B-General_Concept
system	I-General_Concept
,	O
and	O
agreed	O
to	O
join	O
Microsoft	O
on	O
the	O
condition	O
that	O
he	O
be	O
able	O
to	O
bring	O
a	O
number	O
of	O
staff	O
members	O
from	O
his	O
team	O
at	O
DEC	O
with	O
him	O
.	O
</s>
<s>
Cutler	O
arrived	O
at	O
Microsoft	O
in	O
October	O
1988	O
,	O
and	O
began	O
working	O
on	O
the	O
development	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
in	O
November	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
was	O
first	O
developed	O
as	O
a	O
revised	O
version	O
of	O
OS/2	B-Application
,	O
an	O
operating	B-General_Concept
system	I-General_Concept
Microsoft	O
had	O
jointly	O
developed	O
with	O
IBM	O
.	O
</s>
<s>
While	O
OS/2	B-Application
was	O
originally	O
intended	O
to	O
succeed	O
MS-DOS	B-Application
,	O
it	O
had	O
yet	O
to	O
be	O
commercially	O
successful	O
.	O
</s>
<s>
The	O
OS	O
was	O
to	O
be	O
designed	O
so	O
it	O
could	O
be	O
ported	O
to	O
different	O
processor	O
platforms	B-Device
,	O
and	O
support	O
multiprocessor	B-Operating_System
systems	O
,	O
which	O
few	O
operating	B-General_Concept
systems	I-General_Concept
did	O
at	O
that	O
time	O
.	O
</s>
<s>
To	O
target	O
the	O
enterprise	O
market	O
,	O
the	O
OS	O
was	O
also	O
to	O
support	O
networking	B-Architecture
,	O
the	O
POSIX	O
standard	O
,	O
and	O
a	O
security	O
platform	O
compliant	O
with	O
the	O
"	O
Orange	O
Book	O
"	O
standards	O
;	O
which	O
would	O
require	O
the	O
OS	O
to	O
be	O
a	O
multi-user	B-Operating_System
system	I-Operating_System
with	O
a	O
permission	O
framework	O
and	O
the	O
ability	O
to	O
audit	O
security-related	O
events	O
.	O
</s>
<s>
Both	O
Microsoft	O
and	O
IBM	O
wanted	O
to	O
market	O
an	O
operating	B-General_Concept
system	I-General_Concept
that	O
appealed	O
to	O
corporate	O
"	O
enterprise	B-Application
software	I-Application
"	O
customers	O
.	O
</s>
<s>
That	O
meant	O
greater	O
security	O
,	O
reliability	O
,	O
processing	O
power	O
,	O
and	O
computer	B-Architecture
networking	I-Architecture
features	O
.	O
</s>
<s>
However	O
,	O
since	O
Microsoft	O
also	O
wanted	O
to	O
capture	O
market	O
share	O
from	O
Unix	B-Application
on	O
other	O
computing	B-Device
platforms	I-Device
,	O
they	O
needed	O
a	O
system	O
design	O
that	O
was	O
more	O
portable	B-Architecture
than	O
that	O
of	O
OS/2	B-Application
.	O
</s>
<s>
To	O
this	O
end	O
,	O
Microsoft	O
began	O
by	O
developing	O
and	O
testing	O
their	O
new	O
operating	B-General_Concept
system	I-General_Concept
for	O
a	O
non-x86	O
processor	O
:	O
an	O
emulated	B-Application
version	O
of	O
the	O
Intel	B-General_Concept
i860	I-General_Concept
.	O
</s>
<s>
Alluding	O
to	O
the	O
chip	O
's	O
codename	O
,	O
"	O
N10	O
"	O
,	O
Microsoft	O
codenamed	O
their	O
operating	B-General_Concept
system	I-General_Concept
NT	B-Device
OS/2	I-Device
.	O
</s>
<s>
DEC	O
preemptively	O
sued	O
Microsoft	O
,	O
alleging	O
that	O
they	O
stole	O
code	O
from	O
MICA	B-Operating_System
for	O
use	O
in	O
the	O
new	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
In	O
an	O
out-of-court	O
settlement	O
,	O
Microsoft	O
agreed	O
to	O
make	O
NT	B-Device
OS/2	I-Device
compatible	O
with	O
DEC	O
's	O
Alpha	B-Device
processor	I-Device
.	O
</s>
<s>
By	O
April	O
1989	O
,	O
the	O
NT	B-Device
OS/2	I-Device
kernel	O
could	O
run	O
inside	O
the	O
i860	O
emulator	B-Application
.	O
</s>
<s>
By	O
December	O
they	O
had	O
begun	O
porting	O
NT	B-Device
OS/2	I-Device
to	O
the	O
MIPS	B-Device
R3000	I-Device
processor	O
instead	O
,	O
and	O
completed	O
the	O
task	O
in	O
three	O
months	O
.	O
</s>
<s>
In	O
May	O
1990	O
,	O
Microsoft	O
released	O
Windows	B-Application
3.0	I-Application
,	O
a	O
new	O
version	O
of	O
its	O
MS-DOS-based	O
Windows	B-Application
desktop	O
environment	O
.	O
</s>
<s>
Windows	B-Application
3.0	I-Application
sold	O
well	O
,	O
and	O
the	O
resulting	O
shift	O
in	O
Microsoft	O
's	O
marketing	O
strategy	O
eroded	O
their	O
partnership	O
with	O
IBM	O
—	O
who	O
wanted	O
Microsoft	O
to	O
concentrate	O
solely	O
on	O
developing	O
OS/2	B-Application
as	O
its	O
primary	O
platform	O
as	O
opposed	O
to	O
building	O
their	O
future	O
business	O
around	O
Windows	B-Application
.	O
</s>
<s>
Users	O
and	O
developers	O
were	O
unsure	O
of	O
whether	O
to	O
adopt	O
Windows	B-Application
or	O
OS/2	B-Application
due	O
to	O
these	O
uncertainties	O
(	O
a	O
situation	O
magnified	O
by	O
the	O
fact	O
that	O
the	O
operating	B-General_Concept
systems	I-General_Concept
were	O
incompatible	O
with	O
each	O
other	O
at	O
the	O
API	B-Application
level	O
)	O
,	O
while	O
Microsoft	O
's	O
resources	O
were	O
also	O
being	O
drained	O
by	O
the	O
simultaneous	O
development	O
of	O
multiple	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
In	O
August	O
1990	O
,	O
as	O
a	O
response	O
to	O
the	O
popularity	O
of	O
Windows	B-Application
3.0	I-Application
,	O
the	O
NT	B-Device
OS/2	I-Device
team	O
decided	O
to	O
re-work	O
the	O
operating	B-General_Concept
system	I-General_Concept
to	O
use	O
an	O
extended	O
32-bit	O
port	O
of	O
the	O
Windows	B-Library
API	I-Library
known	O
as	O
Win32	B-Library
.	O
</s>
<s>
Win32	B-Library
maintained	O
the	O
familiar	O
structure	O
of	O
the	O
16-bit	B-Device
APIs	B-Application
used	O
by	O
Windows	B-Application
,	O
which	O
would	O
allow	O
developers	O
to	O
easily	O
adapt	O
their	O
software	O
for	O
the	O
new	O
platform	O
while	O
maintaining	O
a	O
level	O
of	O
compatibility	O
with	O
existing	O
software	O
for	O
Windows	B-Application
.	O
</s>
<s>
With	O
the	O
shift	O
to	O
a	O
Windows-like	O
architecture	O
,	O
the	O
operating	B-General_Concept
system	I-General_Concept
's	O
shell	B-Operating_System
was	O
also	O
changed	O
from	O
OS/2	B-Application
'	O
s	O
Presentation	B-Device
Manager	I-Device
to	O
Windows	B-Application
 '	O
Program	O
Manager	O
.	O
</s>
<s>
Neither	O
the	O
general	O
public	O
nor	O
IBM	O
knew	O
about	O
the	O
transformation	O
of	O
NT	B-Device
OS/2	I-Device
into	O
Windows	B-Device
NT	I-Device
at	O
the	O
time	O
.	O
</s>
<s>
Although	O
the	O
companies	O
did	O
agree	O
to	O
a	O
revised	O
partnership	O
where	O
IBM	O
and	O
Microsoft	O
would	O
alternate	O
developing	O
major	O
versions	O
of	O
OS/2	B-Application
instead	O
of	O
collaborating	O
on	O
each	O
version	O
,	O
IBM	O
eventually	O
learned	O
of	O
Microsoft	O
's	O
Windows	B-Device
NT	I-Device
plans	O
in	O
January	O
1991	O
,	O
and	O
immediately	O
ended	O
the	O
OS/2	B-Application
partnership	O
.	O
</s>
<s>
IBM	O
would	O
solely	O
develop	O
OS/2	B-Application
2.0	O
(	O
as	O
was	O
planned	O
under	O
the	O
amended	O
version	O
)	O
and	O
all	O
future	O
versions	O
,	O
without	O
any	O
further	O
involvement	O
from	O
Microsoft	O
.	O
</s>
<s>
In	O
October	O
1991	O
,	O
Windows	B-Device
NT	I-Device
received	O
its	O
first	O
public	O
demonstration	O
at	O
COMDEX	O
.	O
</s>
<s>
In	O
an	O
effort	O
to	O
ensure	O
software	O
taking	O
advantage	O
of	O
Windows	B-Device
NT	I-Device
was	O
available	O
upon	O
its	O
release	O
(	O
scheduled	O
for	O
late-1992	O
)	O
,	O
Microsoft	O
also	O
distributed	O
a	O
32-bit	O
software	B-Application
development	I-Application
kit	I-Application
to	O
selected	O
developers	O
in	O
attendance	O
.	O
</s>
<s>
The	O
demonstration	O
was	O
positively	O
received	O
;	O
PC	O
Magazine	O
called	O
Windows	B-Device
NT	I-Device
"	O
the	O
modern	O
reinvention	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
"	O
,	O
but	O
at	O
the	O
same	O
time	O
claimed	O
that	O
it	O
was	O
unlikely	O
that	O
the	O
promised	O
backward	B-General_Concept
compatibility	I-General_Concept
would	O
be	O
kept	O
for	O
the	O
final	O
release	O
.	O
</s>
<s>
In	O
March	O
1992	O
,	O
Microsoft	O
also	O
released	O
Win32s	B-Library
,	O
which	O
would	O
allow	O
Windows	B-Application
3.1	I-Application
to	O
have	O
partial	O
compatibility	O
with	O
Windows	B-Device
NT	I-Device
programs	O
for	O
the	O
purposes	O
of	O
developing	O
software	O
optimized	O
for	O
the	O
platform	O
.	O
</s>
<s>
At	O
Microsoft	O
's	O
Win32	B-Library
Professional	O
Developers	O
Conference	O
in	O
June	O
1992	O
,	O
Windows	B-Device
NT	I-Device
was	O
demonstrated	O
running	O
on	O
x86	B-Operating_System
and	O
MIPS	B-Device
processors	O
,	O
while	O
a	O
beta	O
version	O
of	O
Windows	B-Device
NT	I-Device
and	O
an	O
updated	O
development	B-Application
kit	I-Application
were	O
also	O
made	O
available	O
.	O
</s>
<s>
Concurrently	O
,	O
Microsoft	O
announced	O
a	O
new	O
version	O
of	O
its	O
SQL	B-Application
Server	I-Application
product	O
for	O
Windows	B-Device
NT	I-Device
;	O
Unix	B-Application
vendors	O
feared	O
that	O
the	O
software	O
could	O
be	O
a	O
killer	O
app	O
that	O
would	O
affect	O
the	O
market	O
share	O
of	O
Unix	B-Application
systems	I-Application
.	O
</s>
<s>
Concerns	O
were	O
also	O
raised	O
over	O
NT	O
's	O
memory	O
usage	O
;	O
while	O
most	O
computers	O
of	O
the	O
era	O
shipped	O
with	O
4	O
megabytes	O
of	O
RAM	B-Architecture
,	O
16	O
MB	O
was	O
recommended	O
for	O
NTs	O
.	O
</s>
<s>
Due	O
to	O
the	O
high	O
cost	O
of	O
RAM	B-Architecture
at	O
the	O
time	O
,	O
critics	O
thought	O
that	O
its	O
high	O
system	O
requirements	O
could	O
affect	O
the	O
sales	O
and	O
adoption	O
of	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
Steps	O
were	O
taken	O
to	O
reduce	O
its	O
memory	O
usage	O
through	O
methods	O
such	O
as	O
paging	B-Architecture
.	O
</s>
<s>
Microsoft	O
began	O
releasing	O
public	O
beta	O
builds	O
of	O
NT	O
in	O
October	O
1992	O
,	O
and	O
a	O
month	O
later	O
at	O
COMDEX	O
,	O
a	O
presentation	O
focusing	O
on	O
third-party	O
software	O
for	O
Windows	B-Device
NT	I-Device
was	O
held	O
.	O
</s>
<s>
The	O
final	O
pre-release	O
version	O
of	O
NT	O
was	O
released	O
in	O
March	O
1993	O
,	O
alongside	O
the	O
unveiling	O
of	O
the	O
server	O
version	O
,	O
LAN	B-Algorithm
Manager	I-Algorithm
for	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
and	O
Windows	B-Device
NT	I-Device
3.1	I-Device
Advanced	O
Server	O
(	O
so	O
numbered	O
to	O
associate	O
them	O
with	O
Windows	B-Application
3.1	I-Application
)	O
were	O
released	O
on	O
July	O
26	O
,	O
1993	O
.	O
</s>
<s>
At	O
first	O
,	O
only	O
the	O
x86	B-Operating_System
and	O
MIPS	B-Device
versions	O
shipped	O
;	O
the	O
DEC	B-Device
Alpha	I-Device
version	O
followed	O
in	O
September	O
.	O
</s>
<s>
Microsoft	O
sold	O
the	O
workstation	B-Device
version	O
for	O
,	O
and	O
the	O
server	O
version	O
for	O
.	O
</s>
<s>
The	O
service	O
packs	O
were	O
distributed	O
on	O
CD-ROM	O
and	O
floppy	O
disk	O
,	O
and	O
also	O
through	O
bulletin	B-Application
board	I-Application
systems	I-Application
,	O
CompuServe	O
,	O
and	O
the	O
Internet	O
.	O
</s>
<s>
Microsoft	O
terminated	O
support	O
for	O
the	O
operating	B-General_Concept
system	I-General_Concept
on	O
December	O
31	O
,	O
2000	O
.	O
</s>
<s>
Support	O
for	O
Windows	B-Device
NT	I-Device
3.1	I-Device
RTM	O
(	O
without	O
a	O
service	O
pack	O
)	O
ended	O
on	O
January	O
8	O
,	O
1994	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
was	O
localized	O
into	O
various	O
languages	O
.	O
</s>
<s>
The	O
version	O
for	O
workstations	B-Device
,	O
but	O
not	O
Windows	B-Device
NT	I-Device
3.1	I-Device
Server	O
,	O
was	O
additionally	O
available	O
in	O
Danish	O
,	O
Finnish	O
,	O
Italian	O
,	O
Norwegian	O
and	O
Portuguese	O
.	O
</s>
<s>
Cutler	O
set	O
three	O
main	O
goals	O
for	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
The	O
first	O
goal	O
was	O
portability	B-Architecture
:	O
in	O
contrast	O
to	O
previous	O
operating	B-General_Concept
systems	I-General_Concept
,	O
which	O
were	O
strongly	O
tied	O
to	O
one	O
architecture	O
,	O
Windows	B-Device
NT	I-Device
should	O
be	O
able	O
to	O
operate	O
on	O
multiple	O
architectures	O
.	O
</s>
<s>
To	O
meet	O
this	O
goal	O
,	O
most	O
of	O
the	O
operating	B-General_Concept
systems	I-General_Concept
,	O
including	O
the	O
operating	B-General_Concept
system	I-General_Concept
core	O
,	O
had	O
to	O
be	O
written	O
in	O
the	O
C	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
During	O
the	O
planning	O
phase	O
it	O
was	O
clear	O
that	O
this	O
would	O
cause	O
Windows	B-Device
NT	I-Device
to	O
have	O
higher	O
memory	O
consumption	O
than	O
all	O
previous	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Besides	O
the	O
graphics	O
system	O
and	O
parts	O
of	O
the	O
networking	B-Architecture
system	O
,	O
which	O
were	O
written	O
in	O
C++	B-Language
,	O
only	O
parts	O
of	O
the	O
operating	B-General_Concept
systems	I-General_Concept
which	O
required	O
direct	O
hardware	O
access	O
and	O
performance	O
critical	O
functions	O
were	O
written	O
in	O
assembly	B-Language
language	I-Language
.	O
</s>
<s>
These	O
parts	O
were	O
isolated	O
so	O
that	O
they	O
could	O
easily	O
be	O
rewritten	O
when	O
porting	O
the	O
operating	B-General_Concept
system	I-General_Concept
to	O
a	O
new	O
architecture	O
.	O
</s>
<s>
This	O
way	O
,	O
the	O
operating	B-General_Concept
system	I-General_Concept
should	O
be	O
made	O
attractive	O
for	O
critical	O
applications	B-Application
.	O
</s>
<s>
To	O
meet	O
this	O
goal	O
,	O
the	O
architecture	O
of	O
Windows	B-Device
NT	I-Device
was	O
designed	O
so	O
that	O
the	O
operating	B-General_Concept
system	I-General_Concept
core	O
was	O
isolated	O
and	O
applications	B-Application
could	O
not	O
access	O
it	O
directly	O
.	O
</s>
<s>
The	O
kernel	O
was	O
designed	O
as	O
a	O
microkernel	B-Operating_System
and	O
components	O
of	O
the	O
core	O
were	O
to	O
run	O
atop	O
the	O
kernel	O
in	O
a	O
modular	O
fashion	O
;	O
Cutler	O
knew	O
this	O
principle	O
from	O
his	O
work	O
at	O
Digital	O
.	O
</s>
<s>
Reliability	O
also	O
includes	O
security	O
,	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
should	O
be	O
able	O
to	O
resist	O
external	O
attacks	O
.	O
</s>
<s>
Mainframes	B-Architecture
already	O
had	O
a	O
system	O
where	O
every	O
user	O
had	O
their	O
own	O
account	O
which	O
was	O
assigned	O
specific	O
rights	O
by	O
the	O
administrator	O
,	O
this	O
way	O
,	O
users	O
could	O
be	O
prevented	O
access	O
to	O
confidential	O
documents	O
.	O
</s>
<s>
A	O
virtual	B-Architecture
memory	I-Architecture
management	O
was	O
designed	O
to	O
thwart	O
attacks	O
by	O
malware	O
and	O
prevent	O
users	O
from	O
accessing	O
foreign	O
areas	O
of	O
memory	O
.	O
</s>
<s>
The	O
third	O
goal	O
was	O
called	O
personality	O
:	O
The	O
operating	B-General_Concept
system	I-General_Concept
should	O
be	O
able	O
to	O
run	O
applications	B-Application
designed	O
for	O
various	O
operating	B-General_Concept
systems	I-General_Concept
,	O
such	O
as	O
Windows	B-Application
,	O
MS-DOS	B-Application
and	O
OS/2	B-Application
applications	B-Application
.	O
</s>
<s>
The	O
Mach	B-Operating_System
kernel	I-Operating_System
followed	O
a	O
similar	O
concept	O
by	O
moving	O
the	O
APIs	B-Application
to	O
components	O
which	O
operated	O
in	O
user	O
mode	O
as	O
applications	B-Application
,	O
these	O
could	O
be	O
changed	O
and	O
new	O
ones	O
could	O
be	O
added	O
.	O
</s>
<s>
This	O
principle	O
was	O
applied	O
to	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
Despite	O
all	O
these	O
goals	O
,	O
the	O
performance	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
was	O
optimized	O
where	O
possible	O
,	O
by	O
adapting	O
critical	O
sections	O
of	O
the	O
code	O
to	O
fast	O
execution	O
speed	O
.	O
</s>
<s>
To	O
improve	O
networking	B-Architecture
performance	O
,	O
large	O
parts	O
of	O
the	O
networking	B-Architecture
system	O
were	O
moved	O
to	O
the	O
operating	B-General_Concept
system	I-General_Concept
core	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
was	O
designed	O
as	O
a	O
networking	B-Architecture
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Cutler	O
hoped	O
to	O
gain	O
additional	O
customers	O
with	O
a	O
reliable	O
networking	B-Architecture
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Bill	O
Gates	O
already	O
dominated	O
the	O
market	O
of	O
desktop	B-General_Concept
operating	I-General_Concept
systems	I-General_Concept
with	O
MS-DOS	B-Application
and	O
Windows	B-Application
and	O
hoped	O
to	O
do	O
the	O
same	O
in	O
the	O
networking	B-Architecture
market	O
with	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
He	O
especially	O
hoped	O
to	O
find	O
a	O
market	O
in	O
the	O
emerging	O
number	O
of	O
servers	B-Application
,	O
while	O
at	O
the	O
same	O
time	O
he	O
did	O
not	O
expect	O
a	O
success	O
in	O
the	O
desktop	O
market	O
until	O
1995	O
.	O
</s>
<s>
Therefore	O
,	O
Windows	B-Device
NT	I-Device
was	O
positioned	O
as	O
a	O
high-end	O
operating	B-General_Concept
system	I-General_Concept
in	O
an	O
interview	O
with	O
the	O
product	O
manager	O
David	O
Thacher	O
.	O
</s>
<s>
It	O
was	O
not	O
designed	O
to	O
replace	O
Windows	B-Application
3.1	I-Application
completely	O
,	O
but	O
it	O
should	O
rather	O
supplement	O
Microsoft	O
's	O
product	O
palette	O
with	O
an	O
operating	B-General_Concept
system	I-General_Concept
for	O
critical	O
applications	B-Application
.	O
</s>
<s>
The	O
expectations	O
were	O
10%	O
to	O
20%	O
among	O
all	O
Windows	B-Application
sales	O
and	O
a	O
market	O
share	O
of	O
10%	O
in	O
the	O
high	O
end	O
market	O
,	O
which	O
amounted	O
to	O
one	O
million	O
copies	O
.	O
</s>
<s>
While	O
Windows	B-Device
NT	I-Device
3.1	I-Device
uses	O
the	O
same	O
graphical	O
user	O
interface	O
as	O
Windows	B-Application
3.1	I-Application
,	O
it	O
was	O
developed	O
anew	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
is	O
not	O
DOS-based	O
,	O
but	O
an	O
independent	O
32-bit	O
operating	B-General_Concept
system	I-General_Concept
;	O
many	O
concepts	O
were	O
taken	O
from	O
Cutler	O
's	O
previous	O
operating	B-General_Concept
system	I-General_Concept
,	O
VMS	B-Operating_System
.	O
</s>
<s>
The	O
architecture	O
of	O
Windows	B-Device
NT	I-Device
takes	O
some	O
ideas	O
of	O
the	O
client	B-Operating_System
–	I-Operating_System
server	I-Operating_System
model	I-Operating_System
,	O
like	O
the	O
modular	O
structure	O
and	O
the	O
communication	O
between	O
the	O
modules	O
.	O
</s>
<s>
System	O
resources	O
like	O
memory	O
,	O
files	O
or	O
devices	O
are	O
viewed	O
as	O
objects	O
by	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
which	O
are	O
all	O
accessed	O
in	O
the	O
same	O
way	O
through	O
handles	O
and	O
which	O
can	O
in	O
this	O
way	O
be	O
secured	O
against	O
unauthorized	O
access	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
was	O
designed	O
for	O
multiprocessor	B-Operating_System
systems	O
;	O
it	O
supports	O
preemptive	O
multitasking	B-Operating_System
and	O
can	O
make	O
use	O
of	O
threads	B-Operating_System
to	O
run	O
multiple	O
processes	O
in	O
parallel	O
.	O
</s>
<s>
Using	O
symmetric	B-Operating_System
multiprocessing	I-Operating_System
,	O
the	O
processing	O
usage	O
is	O
evenly	O
distributed	O
among	O
all	O
available	O
processors	O
.	O
</s>
<s>
The	O
inter-process	B-Operating_System
communication	I-Operating_System
in	O
Windows	B-Device
NT	I-Device
3.1	I-Device
is	O
designed	O
around	O
networks	O
;	O
two	O
newly	O
introduced	O
functions	O
,	O
Remote	B-Operating_System
Procedure	I-Operating_System
Call	I-Operating_System
(	O
RPC	O
)	O
and	O
Network	B-Operating_System
DDE	I-Operating_System
,	O
an	O
extension	O
of	O
Dynamic	B-Operating_System
Data	I-Operating_System
Exchange	I-Operating_System
(	O
DDE	O
)	O
,	O
facilitate	O
the	O
access	O
and	O
data	O
exchange	O
between	O
processes	O
running	O
on	O
different	O
computers	O
inside	O
a	O
network	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
is	O
designed	O
to	O
combine	O
certain	O
elements	O
of	O
a	O
monolithic	B-Operating_System
kernel	I-Operating_System
and	O
a	O
microkernel	B-Operating_System
;	O
nowadays	O
this	O
is	O
most	O
often	O
referred	O
to	O
as	O
a	O
hybrid	B-Operating_System
kernel	I-Operating_System
.	O
</s>
<s>
The	O
hardware	B-Operating_System
abstraction	I-Operating_System
layer	I-Operating_System
represents	O
the	O
lowermost	O
layer	O
and	O
isolates	O
the	O
operating	B-General_Concept
system	I-General_Concept
from	O
the	O
underlying	O
hardware	O
to	O
make	O
it	O
easy	O
to	O
port	O
the	O
operating	B-General_Concept
system	I-General_Concept
to	O
other	O
platforms	B-Device
.	O
</s>
<s>
The	O
kernel	O
running	O
atop	O
only	O
has	O
very	O
basic	O
functions	O
like	O
interrupt	B-Application
management	O
and	O
processor	O
synchronization	O
.	O
</s>
<s>
All	O
other	O
functions	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
core	O
are	O
handled	O
by	O
modules	O
which	O
operate	O
independently	O
from	O
one	O
another	O
and	O
can	O
be	O
swapped	O
without	O
affecting	O
the	O
rest	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Positioned	O
above	O
the	O
operating	B-General_Concept
system	I-General_Concept
core	O
are	O
the	O
subsystems	O
.	O
</s>
<s>
There	O
are	O
two	O
types	O
of	O
subsystems	O
:	O
one	O
are	O
the	O
integral	O
subsystems	O
,	O
which	O
perform	O
important	O
operating	B-General_Concept
system	I-General_Concept
functions	O
.	O
</s>
<s>
The	O
other	O
type	O
of	O
subsystem	O
is	O
the	O
environment	O
subsystem	O
,	O
which	O
exposes	O
the	O
operating	B-General_Concept
system	I-General_Concept
functions	O
to	O
applications	B-Application
via	O
application	B-Application
programming	I-Application
interfaces	I-Application
.	O
</s>
<s>
The	O
base	O
subsystem	O
is	O
the	O
32-bit	O
subsystem	O
which	O
runs	O
32-bit	O
applications	B-Application
written	O
for	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
applications	B-Application
can	O
only	O
run	O
on	O
one	O
platform	O
,	O
and	O
must	O
be	O
recompiled	O
for	O
every	O
platform	O
.	O
</s>
<s>
The	O
32-bit	O
subsystem	O
also	O
contains	O
all	O
output	B-General_Concept
functions	O
,	O
including	O
the	O
Graphics	B-Operating_System
Device	I-Operating_System
Interface	I-Operating_System
(	O
GDI	O
)	O
,	O
so	O
all	O
other	O
subsystems	O
have	O
to	O
call	O
the	O
32-bit	O
subsystem	O
to	O
be	O
able	O
to	O
output	B-General_Concept
text	O
or	O
graphics	O
.	O
</s>
<s>
Other	O
subsystems	O
contained	O
in	O
Windows	B-Device
NT	I-Device
3.1	I-Device
are	O
the	O
POSIX	O
subsystem	O
,	O
which	O
supports	O
POSIX-compatible	O
applications	B-Application
built	O
for	O
Windows	B-Device
NT	I-Device
,	O
and	O
,	O
in	O
the	O
x86	B-Operating_System
version	O
only	O
,	O
the	O
OS/2	B-Application
subsystem	O
,	O
which	O
allows	O
command-line	O
based	O
OS/2	B-Application
1.x	O
applications	B-Application
to	O
run	O
.	O
</s>
<s>
The	O
Virtual	O
DOS	B-Device
Machine	O
(	O
VDM	O
)	O
is	O
sometimes	O
also	O
viewed	O
as	O
a	O
subsystem	O
,	O
but	O
is	O
,	O
strictly	O
speaking	O
,	O
a	O
normal	O
32-bit	B-Application
Windows	I-Application
application	O
.	O
</s>
<s>
It	O
manages	O
applications	B-Application
originally	O
built	O
for	O
DOS	B-Device
.	O
</s>
<s>
Built	O
on	O
top	O
is	O
Windows	B-Application
on	I-Application
Windows	I-Application
(	O
WoW	O
)	O
,	O
which	O
allows	O
applications	B-Application
built	O
for	O
16-bit	B-Library
Windows	I-Library
operating	B-General_Concept
systems	I-General_Concept
like	O
Windows	B-Application
3.1	I-Application
to	O
run	O
.	O
</s>
<s>
On	O
x86	B-Operating_System
computers	O
,	O
the	O
virtual	O
DOS	B-Device
machine	O
uses	O
the	O
virtual	B-Application
8086	I-Application
mode	I-Application
to	O
run	O
DOS	B-Device
applications	B-Application
directly	O
,	O
on	O
RISC	B-Architecture
computers	O
,	O
an	O
emulator	B-Application
licensed	O
from	O
Insignia	O
Solutions	O
is	O
used	O
which	O
emulates	B-Application
a	O
80286	B-General_Concept
processor	O
.	O
</s>
<s>
However	O
,	O
not	O
all	O
DOS	B-Device
and	O
16-bit	B-Library
Windows	I-Library
applications	B-Application
can	O
be	O
run	O
on	O
Windows	B-Device
NT	I-Device
3.1	I-Device
due	O
to	O
various	O
limitations	O
,	O
one	O
of	O
them	O
being	O
the	O
inability	O
of	O
applications	B-Application
to	O
directly	O
access	O
the	O
hardware	O
.	O
</s>
<s>
As	O
well	O
,	O
VxD	B-Application
files	O
sometimes	O
needed	O
by	O
applications	B-Application
cannot	O
be	O
used	O
with	O
Windows	B-Device
NT	I-Device
3.1	I-Device
.	O
</s>
<s>
While	O
pure	O
DOS	B-Device
applications	B-Application
are	O
run	O
in	O
separate	O
memory	O
spaces	O
,	O
16-bit	B-Library
Windows	I-Library
applications	B-Application
have	O
to	O
share	O
one	O
memory	O
space	O
.	O
</s>
<s>
While	O
this	O
is	O
done	O
due	O
to	O
compatibility	O
reasons	O
with	O
applications	B-Application
which	O
depend	O
on	O
this	O
ability	O
,	O
like	O
Schedule+	B-Application
and	O
Microsoft	B-Application
Mail	I-Application
,	O
it	O
also	O
means	O
that	O
16-bit	B-Library
Windows	I-Library
applications	B-Application
only	O
run	O
in	O
cooperative	B-Operating_System
multitasking	I-Operating_System
.	O
</s>
<s>
A	O
faulty	O
16-bit	B-Library
Windows	I-Library
application	O
is	O
in	O
this	O
way	O
able	O
to	O
cause	O
all	O
other	O
16-bit	B-Library
Windows	I-Library
applications	B-Application
(	O
but	O
not	O
Windows	B-Device
NT	I-Device
itself	O
)	O
to	O
crash	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
provides	O
a	O
boot	B-Application
manager	I-Application
called	O
NTLDR	B-Application
which	O
is	O
loaded	O
during	O
the	O
startup	O
process	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
on	O
x86-based	O
computers	O
.	O
</s>
<s>
It	O
allows	O
a	O
multiboot	O
setup	O
of	O
multiple	O
instances	O
of	O
Windows	B-Device
NT	I-Device
3.1	I-Device
,	O
as	O
well	O
as	O
MS-DOS	B-Application
and	O
OS/2	B-Application
1.x	O
.	O
</s>
<s>
NTLDR	B-Application
is	O
not	O
used	O
for	O
the	O
RISC	B-Architecture
versions	O
because	O
the	O
RISC	B-Architecture
computers	O
 '	O
firmware	O
provides	O
their	O
own	O
boot	B-Application
manager	I-Application
.	O
</s>
<s>
Every	O
user	O
has	O
to	O
log	O
on	O
to	O
the	O
computer	O
after	O
Windows	B-Device
NT	I-Device
3.1	I-Device
is	O
booted	O
up	O
by	O
pressing	O
the	O
key	O
combination	O
Ctrl+Alt+Del	B-Device
and	O
entering	O
the	O
user	O
name	O
and	O
password	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
introduced	O
the	O
new	O
NTFS	B-Application
file	I-Application
system	I-Application
.	O
</s>
<s>
NTFS	B-Application
supports	O
long	O
file	O
names	O
and	O
has	O
features	O
to	O
accommodate	O
POSIX	O
applications	B-Application
like	O
hard	B-Application
links	I-Application
.	O
</s>
<s>
For	O
compatibility	O
reasons	O
,	O
Windows	B-Device
NT	I-Device
3.1	I-Device
also	O
supports	O
FAT16	B-Application
as	O
well	O
as	O
OS/2	B-Application
'	O
s	O
file	O
system	O
HPFS	B-Application
,	O
but	O
does	O
not	O
support	O
long	O
file	O
names	O
on	O
FAT	O
file	O
system	O
(	O
VFAT	B-Application
)	O
.	O
</s>
<s>
This	O
was	O
added	O
in	O
Windows	B-Device
NT	I-Device
3.5	I-Device
.	O
</s>
<s>
Designed	O
as	O
a	O
networking	B-Architecture
operating	B-General_Concept
system	I-General_Concept
,	O
Windows	B-Device
NT	I-Device
3.1	I-Device
supports	O
multiple	O
network	O
protocols	O
.	O
</s>
<s>
Besides	O
IPX/SPX	B-Protocol
and	O
NetBEUI	B-Protocol
,	O
the	O
TCP/IP	B-Protocol
protocol	I-Protocol
is	O
supported	O
allowing	O
access	O
to	O
the	O
Internet	O
.	O
</s>
<s>
Similar	O
to	O
Windows	B-Application
for	O
Workgroups	O
,	O
files	O
and	O
printers	O
can	O
be	O
shared	O
and	O
the	O
access	O
rights	O
and	O
configuration	O
of	O
these	O
resources	O
can	O
be	O
edited	O
over	O
the	O
network	O
.	O
</s>
<s>
The	O
Remote	B-Device
Access	I-Device
Service	I-Device
(	O
RAS	O
)	O
allows	O
a	O
client	O
from	O
outside	O
the	O
network	O
to	O
connect	O
to	O
the	O
network	O
using	O
a	O
modem	B-Application
,	O
ISDN	B-Protocol
or	O
X.25	B-Protocol
and	O
access	O
its	O
resources	O
.	O
</s>
<s>
While	O
the	O
workstation	B-Device
allows	O
one	O
RAS	O
connection	O
at	O
a	O
time	O
,	O
the	O
server	O
supports	O
64	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
supports	O
the	O
then-new	O
Unicode	O
standard	O
,	O
a	O
character	B-General_Concept
set	I-General_Concept
which	O
allows	O
multiple	O
languages	O
to	O
be	O
displayed	O
.	O
</s>
<s>
This	O
facilitates	O
localization	B-General_Concept
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
All	O
strings	O
,	O
as	O
well	O
as	O
file	O
and	O
folder	O
names	O
,	O
are	O
internally	O
processed	O
in	O
Unicode	O
,	O
but	O
the	O
included	O
programs	O
,	O
like	O
the	O
File	B-Application
Manager	I-Application
,	O
are	O
not	O
Unicode	O
aware	O
,	O
so	O
folders	O
containing	O
Unicode	O
characters	O
cannot	O
be	O
accessed	O
.	O
</s>
<s>
For	O
demonstration	O
purposes	O
,	O
a	O
Unicode	O
typeface	O
called	O
Lucida	O
Sans	O
Unicode	O
is	O
shipped	O
with	O
Windows	B-Device
NT	I-Device
3.1	I-Device
even	O
though	O
it	O
is	O
not	O
installed	O
by	O
default	O
.	O
</s>
<s>
The	O
Windows	B-Protocol
registry	I-Protocol
,	O
introduced	O
with	O
Windows	B-Application
3.1	I-Application
,	O
is	O
a	O
central	O
,	O
hierarchical	O
configuration	O
database	O
designed	O
to	O
allow	O
configuration	O
of	O
computers	O
over	O
the	O
network	O
and	O
to	O
replace	O
the	O
commonly-used	O
text-based	O
configuration	O
files	O
,	O
like	O
INI	B-Protocol
files	I-Protocol
,	O
AUTOEXEC.BAT	O
and	O
CONFIG.SYS	B-Device
.	O
</s>
<s>
Using	O
the	O
undocumented	O
registry	B-Protocol
editor	I-Protocol
,	O
the	O
Windows	B-Protocol
registry	I-Protocol
can	O
be	O
viewed	O
and	O
edited	O
by	O
the	O
user	O
.	O
</s>
<s>
The	O
Advanced	O
Server	O
is	O
designed	O
to	O
manage	O
the	O
workstation	B-Device
computers	I-Device
.	O
</s>
<s>
It	O
can	O
function	O
as	O
a	O
Domain	B-Protocol
controller	I-Protocol
,	O
where	O
all	O
users	O
and	O
groups	O
as	O
well	O
as	O
their	O
rights	O
are	O
stored	O
.	O
</s>
<s>
Using	O
the	O
replication	B-Architecture
service	O
,	O
files	O
like	O
logon	O
scripts	O
can	O
be	O
synchronized	O
across	O
all	O
computers	O
on	O
the	O
network	O
.	O
</s>
<s>
The	O
Advanced	O
Server	O
supports	O
the	O
AppleTalk	B-Application
protocol	O
to	O
allow	O
connections	O
to	O
Macintosh	O
computers	O
.	O
</s>
<s>
Hard	O
drives	O
can	O
be	O
combined	O
to	O
RAIDs	B-Architecture
in	O
Windows	B-Device
NT	I-Device
3.1	I-Device
Advanced	O
Server	O
,	O
the	O
supported	O
configurations	O
are	O
RAID	B-Architecture
0	O
,	O
RAID	B-Architecture
1	O
and	O
RAID	B-Architecture
5	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
,	O
for	O
the	O
most	O
part	O
,	O
comes	O
with	O
32-bit	O
versions	O
of	O
the	O
components	O
featured	O
in	O
Windows	B-Application
3.1	I-Application
and	O
Windows	B-Application
for	O
Workgroups	O
.	O
</s>
<s>
However	O
,	O
it	O
also	O
included	O
applications	B-Application
specifically	O
aimed	O
at	O
the	O
needs	O
of	O
Windows	B-Device
NT	I-Device
,	O
like	O
the	O
User	O
Manager	O
,	O
the	O
Performance	B-Device
Monitor	I-Device
,	O
the	O
Disk	O
Administrator	O
,	O
the	O
Event	O
Viewer	O
and	O
the	O
Backup	O
application	O
.	O
</s>
<s>
Because	O
Windows	B-Device
NT	I-Device
3.1	I-Device
is	O
not	O
DOS-based	O
,	O
a	O
new	O
32-bit	O
command-line	O
processor	O
,	O
called	O
CMD.EXE	B-Device
was	O
included	O
which	O
was	O
compatible	O
with	O
MS-DOS	B-Application
5.0	O
.	O
</s>
<s>
For	O
compatibility	O
reasons	O
,	O
Windows	B-Device
NT	I-Device
3.1	I-Device
shipped	O
with	O
a	O
few	O
16-bit	B-Device
applications	B-Application
,	O
like	O
Microsoft	B-Application
Write	I-Application
or	O
EDLIN	B-Application
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
,	O
being	O
an	O
all-new	O
operating	B-General_Concept
system	I-General_Concept
for	O
which	O
no	O
previous	O
drivers	O
could	O
be	O
used	O
,	O
includes	O
a	O
wealth	O
of	O
drivers	O
for	O
various	O
common	O
components	O
and	O
peripherals	O
.	O
</s>
<s>
This	O
includes	O
common	O
SCSI	B-Architecture
devices	O
like	O
hard	O
drives	O
,	O
CD-ROM	O
drives	O
,	O
tape	O
drives	O
and	O
image	B-Application
scanners	I-Application
,	O
as	O
well	O
as	O
ISA	B-Architecture
devices	O
like	O
graphics	O
cards	O
,	O
sound	O
cards	O
and	O
network	O
cards	O
.	O
</s>
<s>
The	O
PCI	B-Protocol
bus	I-Protocol
,	O
however	O
,	O
is	O
expressly	O
not	O
supported	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
supports	O
an	O
uninterruptible	O
power	O
supply	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
could	O
be	O
installed	O
either	O
by	O
using	O
the	O
CD-ROM	O
and	O
a	O
provided	O
boot	B-Operating_System
disk	I-Operating_System
,	O
or	O
by	O
utilizing	O
a	O
set	O
of	O
twenty-two	O
3.5	O
"	O
floppies	O
(	O
twenty-three	O
floppies	O
for	O
Advanced	O
Server	O
)	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
could	O
also	O
be	O
installed	O
over	O
the	O
network	O
.	O
</s>
<s>
Compared	O
to	O
the	O
floppies	O
,	O
the	O
CD-ROM	O
contained	O
additional	O
drivers	O
and	O
applications	B-Application
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
supports	O
multiple	B-Operating_System
platforms	I-Operating_System
:	O
Aside	O
from	O
the	O
x86	B-Operating_System
architecture	I-Operating_System
,	O
it	O
runs	O
on	O
computers	O
with	O
DEC	B-Device
Alpha	I-Device
or	O
MIPS	B-Device
(	O
R4000	B-General_Concept
and	O
R4400	B-General_Concept
)	O
processors	O
.	O
</s>
<s>
Minimum	O
system	O
requirements	O
on	O
x86	B-Operating_System
systems	O
include	O
a	O
25MHz	O
80386	B-General_Concept
processor	O
,	O
at	O
least	O
12	O
megabytes	O
of	O
memory	O
,	O
75	O
megabytes	O
of	O
hard	O
drive	O
space	O
,	O
and	O
a	O
VGA	O
graphics	O
card	O
.	O
</s>
<s>
RISC	B-Architecture
systems	O
require	O
16	O
megabytes	O
of	O
memory	O
,	O
92	O
megabytes	O
of	O
hard	O
drive	O
space	O
,	O
and	O
a	O
CD-ROM	O
drive	O
.	O
</s>
<s>
The	O
Advanced	O
Server	O
edition	O
requires	O
an	O
80386	B-General_Concept
processor	O
with	O
16	O
megabytes	O
of	O
memory	O
and	O
90	O
megabytes	O
of	O
hard	O
drive	O
space	O
.	O
</s>
<s>
On	O
RISC	B-Architecture
systems	O
,	O
110	O
megabytes	O
of	O
hard	O
drive	O
space	O
is	O
needed	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
supports	O
dual	O
processor	O
systems	O
,	O
while	O
the	O
Advanced	O
Server	O
edition	O
supports	O
up	O
to	O
four	O
processors	O
.	O
</s>
<s>
Due	O
to	O
an	O
error	O
in	O
the	O
processor	O
detection	O
routine	O
,	O
Windows	B-Device
NT	I-Device
3.1	I-Device
cannot	O
be	O
installed	O
on	O
Pentium	B-General_Concept
II	I-General_Concept
or	O
newer	O
processors	O
.	O
</s>
<s>
Windows	B-Device
NT	I-Device
3.1	I-Device
sold	O
about	O
300,000	O
copies	O
in	O
its	O
first	O
year	O
.	O
</s>
<s>
The	O
hardware	O
requirements	O
were	O
deemed	O
to	O
be	O
very	O
high	O
at	O
that	O
time	O
;	O
the	O
recommended	O
system	O
requirements	O
of	O
a	O
486	O
processor	O
with	O
16	O
megabytes	O
of	O
memory	O
were	O
well	O
above	O
the	O
average	O
computer	O
's	O
configuration	O
,	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
turned	O
out	O
to	O
be	O
too	O
slow	O
to	O
use	O
.	O
</s>
<s>
32-bit	O
applications	B-Application
which	O
could	O
have	O
used	O
the	O
capabilities	O
of	O
Windows	B-Device
NT	I-Device
3.1	I-Device
were	O
scarce	O
,	O
so	O
users	O
had	O
to	O
resort	O
to	O
the	O
old	O
16-bit	B-Device
applications	B-Application
;	O
however	O
,	O
these	O
ran	O
slower	O
than	O
on	O
Windows	B-Application
3.1	I-Application
.	O
</s>
<s>
Estimates	O
in	O
November	O
1993	O
counted	O
only	O
150	O
Windows	B-Device
NT	I-Device
applications	B-Application
.	O
</s>
<s>
Common	O
types	O
of	O
software	O
,	O
like	O
office	O
suites	O
,	O
were	O
not	O
available	O
for	O
Windows	B-Device
NT	I-Device
3.1	I-Device
.	O
</s>
<s>
During	O
the	O
development	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
the	O
API	B-Application
calls	O
were	O
changed	O
so	O
32-bit	O
applications	B-Application
built	O
on	O
the	O
1992	O
pre-release	O
version	O
of	O
Windows	B-Device
NT	I-Device
3.1	I-Device
could	O
not	O
be	O
run	O
on	O
the	O
final	O
version	O
.	O
</s>
<s>
This	O
affected	O
software	O
such	O
as	O
Microsoft	B-Application
Visual	I-Application
C++	I-Application
1.0	O
and	O
Microsoft	O
Fortran	O
PowerStation	O
.	O
</s>
<s>
RISC	B-Architecture
systems	O
with	O
Windows	B-Device
NT	I-Device
3.1	I-Device
had	O
an	O
even	O
bigger	O
disadvantage	O
:	O
even	O
though	O
they	O
were	O
more	O
powerful	O
than	O
x86	B-Operating_System
systems	O
,	O
almost	O
no	O
32-bit	O
applications	B-Application
or	O
drivers	O
were	O
ported	O
to	O
these	O
platforms	B-Device
.	O
</s>
<s>
16-bit	B-Device
applications	B-Application
ran	O
much	O
slower	O
under	O
RISC	B-Architecture
systems	O
because	O
of	O
the	O
80286	B-General_Concept
emulation	B-Application
compared	O
to	O
x86	B-Operating_System
systems	O
which	O
could	O
run	O
16-bit	B-Device
applications	B-Application
natively	O
,	O
and	O
DOS	B-Device
and	O
16-bit	B-Device
applications	B-Application
which	O
depended	O
on	O
386	B-General_Concept
calls	O
could	O
not	O
be	O
run	O
at	O
all	O
on	O
RISC	B-Architecture
systems	O
.	O
</s>
<s>
However	O
,	O
not	O
all	O
reception	O
was	O
negative	O
;	O
the	O
multitasking	B-Operating_System
capabilities	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
were	O
rated	O
positively	O
,	O
especially	O
compared	O
to	O
Windows	B-Application
3.1	I-Application
.	O
</s>
<s>
Compared	O
to	O
the	O
size	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
the	O
installation	O
turned	O
out	O
to	O
be	O
very	O
easy	O
,	O
even	O
though	O
installing	O
from	O
floppies	O
was	O
a	O
very	O
time-consuming	O
task	O
.	O
</s>
<s>
The	O
Advanced	O
Server	O
,	O
intended	O
to	O
be	O
the	O
successor	O
to	O
the	O
unsuccessful	O
LAN	B-Algorithm
Manager	I-Algorithm
product	O
,	O
was	O
technically	O
much	O
superior	O
to	O
its	O
predecessor	O
,	O
and	O
only	O
failed	O
to	O
gain	O
success	O
because	O
it	O
shared	O
the	O
same	O
problems	O
with	O
its	O
workstation	B-Device
pendant	O
,	O
such	O
as	O
the	O
low	O
performance	O
running	O
16-bit	B-Device
applications	B-Application
.	O
</s>
<s>
With	O
Windows	B-Device
NT	I-Device
,	O
Microsoft	O
entered	O
a	O
market	O
it	O
could	O
not	O
previously	O
address	O
and	O
which	O
was	O
mostly	O
dominated	O
by	O
Unix	B-Application
,	O
Novell	O
NetWare	O
and	O
OS/2	B-Application
.	O
</s>
<s>
A	O
test	O
performed	O
by	O
the	O
InfoWorld	O
magazine	O
in	O
November	O
1993	O
,	O
where	O
the	O
networking	B-Architecture
capabilities	O
of	O
several	O
operating	B-General_Concept
systems	I-General_Concept
were	O
tested	O
,	O
showed	O
that	O
Windows	B-Device
NT	I-Device
3.1	I-Device
was	O
seriously	O
lacking	O
in	O
inter-client	O
communication	O
:	O
it	O
could	O
only	O
connect	O
to	O
its	O
own	O
server	O
via	O
NetBEUI	B-Protocol
;	O
attempts	O
to	O
connect	O
to	O
Unix	B-Application
,	O
NetWare	O
and	O
OS/2	B-Application
all	O
failed	O
because	O
no	O
client	O
software	O
was	O
available	O
.	O
</s>
<s>
For	O
the	O
Advanced	O
Server	O
,	O
only	O
their	O
own	O
client	O
,	O
the	O
Macintosh	O
and	O
,	O
if	O
only	O
limited	O
,	O
OS/2	B-Application
were	O
able	O
to	O
connect	O
to	O
the	O
server	O
.	O
</s>
<s>
Even	O
though	O
the	O
operating	B-General_Concept
system	I-General_Concept
's	O
actual	O
success	O
was	O
only	O
moderate	O
,	O
it	O
had	O
a	O
huge	O
lasting	O
impact	O
.	O
</s>
<s>
Developers	O
of	O
Unix	B-Application
derivations	O
for	O
the	O
first	O
time	O
strived	O
to	O
standardize	O
their	O
operating	B-General_Concept
systems	I-General_Concept
,	O
and	O
Novell	O
was	O
so	O
concerned	O
about	O
its	O
market	O
share	O
that	O
it	O
bought	O
a	O
Unix	B-Application
vendor	O
.	O
</s>
<s>
Manufacturers	O
of	O
microprocessors	B-Architecture
hoped	O
to	O
use	O
the	O
portability	B-Architecture
of	O
the	O
new	O
operating	B-General_Concept
system	I-General_Concept
to	O
increase	O
their	O
own	O
sales	O
,	O
and	O
thus	O
ports	O
of	O
Windows	B-Device
NT	I-Device
were	O
announced	O
for	O
various	O
platforms	B-Device
,	O
like	O
the	O
Sun	B-Architecture
SPARC	I-Architecture
architecture	O
and	O
the	O
Clipper	B-General_Concept
architecture	I-General_Concept
.	O
</s>
<s>
It	O
was	O
recognized	O
that	O
Windows	B-Device
NT	I-Device
would	O
dominate	O
the	O
desktop	O
market	O
as	O
soon	O
as	O
the	O
hardware	O
became	O
powerful	O
enough	O
to	O
run	O
the	O
operating	B-General_Concept
system	I-General_Concept
at	O
an	O
acceptable	O
speed	O
.	O
</s>
<s>
Eight	O
years	O
later	O
,	O
Microsoft	O
would	O
unify	O
the	O
consumer-oriented	O
Windows	B-Application
line	O
(	O
which	O
had	O
remained	O
MS-DOS	B-Application
based	O
)	O
with	O
the	O
NT	O
line	O
with	O
the	O
October	O
2001	O
release	O
of	O
Windows	B-Application
XP	I-Application
—	O
the	O
first	O
consumer-oriented	O
version	O
of	O
Windows	B-Application
to	O
use	O
the	O
NT	O
architecture	O
.	O
</s>
