<s>
An	O
autorun.inf	B-Protocol
file	O
is	O
a	O
text	B-General_Concept
file	I-General_Concept
that	O
can	O
be	O
used	O
by	O
the	O
AutoRun	O
and	O
AutoPlay	O
components	O
of	O
Microsoft	B-Application
Windows	I-Application
operating	I-Application
systems	I-Application
.	O
</s>
<s>
For	O
the	O
file	O
to	O
be	O
discovered	O
and	O
used	O
by	O
these	O
component	O
,	O
it	O
must	O
be	O
located	O
in	O
the	O
root	B-Application
directory	I-Application
of	O
a	O
volume	B-Application
.	O
</s>
<s>
As	O
Windows	O
has	O
a	O
case-insensitive	O
view	O
of	O
filenames	B-Device
,	O
the	O
autorun.inf	B-Protocol
file	O
can	O
be	O
stored	O
as	O
AutoRun.inf	B-Protocol
or	O
Autorun.INF	B-Protocol
or	O
any	O
other	O
case	O
combination	O
.	O
</s>
<s>
The	O
AutoRun	O
component	O
was	O
introduced	O
in	O
Windows	B-Application
95	I-Application
as	O
a	O
way	O
of	O
reducing	O
support	O
costs	O
.	O
</s>
<s>
AutoRun	O
enabled	O
application	O
CD-ROMs	B-Device
to	O
automatically	O
launch	O
a	O
program	O
which	O
could	O
then	O
guide	O
the	O
user	O
through	O
the	O
installation	O
process	O
.	O
</s>
<s>
By	O
placing	O
settings	O
in	O
an	O
autorun.inf	B-Protocol
file	O
,	O
manufacturers	O
could	O
decide	O
what	O
actions	O
were	O
taken	O
when	O
their	O
CD-ROM	B-Device
was	O
inserted	O
.	O
</s>
<s>
The	O
simplest	O
autorun.inf	B-Protocol
files	O
have	O
just	O
two	O
settings	O
:	O
one	O
specifying	O
an	O
icon	O
to	O
represent	O
the	O
CD	O
in	O
Windows	B-Protocol
Explorer	I-Protocol
(	O
or	O
"	O
My	O
Computer	O
"	O
)	O
and	O
one	O
specifying	O
which	O
application	O
to	O
run	O
.	O
</s>
<s>
autorun.inf	B-Protocol
is	O
an	O
ASCII	B-Protocol
text	I-Protocol
file	I-Protocol
located	O
in	O
the	O
root	B-Application
folder	I-Application
of	O
a	O
CD-ROM	B-Device
or	O
other	O
volume	B-Application
device	O
medium	O
(	O
See	O
AutoPlay	O
device	O
types	O
)	O
.	O
</s>
<s>
The	O
structure	O
is	O
that	O
of	O
a	O
classic	O
Windows	O
.ini	B-Protocol
file	O
,	O
containing	O
information	O
and	O
commands	O
as	O
"	O
key	O
=	O
value	O
"	O
pairs	O
,	O
grouped	O
into	O
sections	O
.	O
</s>
<s>
Autorun.inf	B-Protocol
has	O
been	O
used	O
to	O
execute	O
a	O
malicious	O
program	O
automatically	O
,	O
without	O
the	O
user	O
knowing	O
.	O
</s>
<s>
This	O
functionality	O
was	O
removed	O
in	O
Windows	B-Device
7	I-Device
and	O
a	O
patch	O
for	O
Windows	O
XP	O
and	O
Vista	O
was	O
released	O
on	O
August	O
25	O
,	O
2009	O
and	O
included	O
in	O
Microsoft	O
Automatic	O
Updates	O
on	O
February	O
8	O
,	O
2011	O
.	O
</s>
<s>
The	O
mere	O
existence	O
of	O
an	O
autorun.inf	B-Protocol
file	O
on	O
a	O
medium	O
does	O
not	O
mean	O
that	O
Windows	O
will	O
automatically	O
read	O
it	O
or	O
use	O
its	O
settings	O
.	O
</s>
<s>
How	O
an	O
inf	O
file	O
is	O
handled	O
depends	O
on	O
the	O
version	O
of	O
Windows	O
in	O
use	O
,	O
the	O
volume	B-Application
drive	O
type	O
and	O
certain	O
Registry	B-Protocol
settings	O
.	O
</s>
<s>
Assuming	O
Registry	B-Protocol
settings	O
allow	O
AutoRun	O
,	O
then	O
the	O
following	O
autorun.inf	B-Protocol
handling	O
takes	O
place	O
:	O
</s>
<s>
On	O
any	O
drive	O
type	O
,	O
the	O
autorun.inf	B-Protocol
is	O
read	O
,	O
parsed	O
and	O
instructions	O
followed	O
immediately	O
and	O
silently	O
.	O
</s>
<s>
Drives	O
of	O
type	O
DRIVE_CDROM	O
invoke	O
AutoPlay	O
if	O
no	O
autorun.inf	B-Protocol
file	O
is	O
found	O
.	O
</s>
<s>
Drives	O
of	O
type	O
DRIVE_REMOVABLE	O
do	O
not	O
use	O
the	O
autorun.inf	B-Protocol
file	O
.	O
</s>
<s>
Drives	O
of	O
type	O
DRIVE_REMOVABLE	O
now	O
use	O
autorun.inf	B-Protocol
but	O
continue	O
to	O
be	O
handled	O
by	O
AutoPlay	O
.	O
</s>
<s>
This	O
simple	O
autorun.inf	B-Protocol
file	O
specifies	O
setup.exe	O
as	O
the	O
application	O
to	O
run	O
when	O
AutoRun	O
is	O
activated	O
.	O
</s>
<s>
Following	O
are	O
the	O
sections	O
and	O
keys	O
allowed	O
in	O
a	O
valid	O
autorun.inf	B-Protocol
.	O
</s>
<s>
An	O
autorun.inf	B-Protocol
file	O
must	O
contain	O
this	O
section	O
to	O
be	O
valid	O
.	O
</s>
<s>
This	O
icon	O
replaces	O
the	O
standard	O
drive	O
icon	O
in	O
Windows	B-Protocol
Explorer	I-Protocol
.	O
</s>
<s>
Specifies	O
a	O
text	O
label	O
representing	O
the	O
drive	O
in	O
Windows	B-Protocol
Explorer	I-Protocol
.	O
</s>
<s>
Use	O
AutoPlay	O
rather	O
than	O
AutoRun	O
with	O
CD-ROMs	B-Device
.	O
</s>
<s>
The	O
action	O
taken	O
on	O
CD-ROM	B-Device
insertion	O
will	O
depend	O
on	O
the	O
version	O
of	O
Windows	O
being	O
used	O
.	O
</s>
<s>
The	O
folder	O
names	O
are	O
always	O
taken	O
as	O
absolute	O
paths	O
(	O
a	O
path	O
from	O
the	O
root	B-Application
directory	I-Application
of	O
the	O
media	O
)	O
whether	O
or	O
not	O
a	O
leading	O
slash	O
is	O
used	O
.	O
</s>
<s>
This	O
prevents	O
a	O
lengthy	O
search	O
through	O
the	O
entire	O
contents	O
of	O
a	O
CD-ROM	B-Device
.	O
</s>
