<s>
In	O
computing	O
,	O
FASTOPEN	B-Device
is	O
a	O
DOS	B-Device
terminate-and-stay-resident	O
command	B-Application
,	O
introduced	O
in	O
MS-DOS	B-Application
version	O
3.3	O
,	O
that	O
provides	O
accelerated	O
access	O
to	O
frequently-used	O
files	B-Application
and	I-Application
directories	I-Application
.	O
</s>
<s>
The	O
command	B-Application
is	O
also	O
available	O
in	O
SISNE	B-Operating_System
plus	I-Operating_System
.	O
</s>
<s>
The	O
command	B-Application
works	O
with	O
hard	B-Device
disks	I-Device
,	O
but	O
not	O
with	O
diskettes	B-Device
(	O
probably	O
for	O
security	O
when	O
swapping	O
)	O
or	O
with	O
network	O
drives	O
(	O
probably	O
because	O
such	O
drives	O
do	O
not	O
offer	O
block-level	O
access	O
,	O
only	O
file-level	O
access	O
)	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
specify	O
for	O
which	O
drives	O
should	O
operate	O
,	O
how	O
many	O
files	B-Application
and	I-Application
directories	I-Application
should	O
be	O
cached	B-Device
on	O
each	O
(	O
10	O
by	O
default	O
,	O
up	O
to	O
999	O
total	O
)	O
,	O
how	O
many	O
regions	O
for	O
each	O
drive	O
should	O
be	O
cached	B-Device
and	O
whether	O
the	O
cache	O
should	O
be	O
located	O
in	O
conventional	O
or	O
expanded	B-Device
memory	I-Device
.	O
</s>
<s>
If	O
a	O
disk	B-Application
defragmenter	I-Application
tool	O
is	O
used	O
,	O
or	O
if	O
Windows	B-Protocol
Explorer	I-Protocol
is	O
to	O
move	O
files	O
or	O
directories	O
,	O
while	O
is	O
installed	O
,	O
it	O
is	O
necessary	O
to	O
reboot	O
the	O
computer	O
afterwards	O
,	O
because	O
would	O
remember	O
the	O
old	O
position	O
of	O
files	B-Application
and	I-Application
directories	I-Application
,	O
causing	O
MS-DOS	B-Application
to	O
display	O
garbage	O
if	O
e.g.	O
</s>
<s>
"	O
DIR	B-Device
"	O
was	O
performed	O
.	O
</s>
<s>
DR	B-Application
DOS	I-Application
6.0	O
includes	O
an	O
implementation	O
of	O
the	O
command	B-Application
.	O
</s>
<s>
is	O
also	O
part	O
of	O
the	O
Windows	B-Application
XP	I-Application
MS-DOS	B-Application
subsystem	O
to	O
maintain	O
MS-DOS	B-Application
and	O
MS	O
OS/2	O
version	O
1.x	O
compatibility	O
.	O
</s>
<s>
It	O
is	O
not	O
available	O
on	O
Windows	B-Application
XP	I-Application
64-Bit	O
Edition	O
.	O
</s>
<s>
The	O
"	O
fastopen	B-Device
"	O
name	O
has	O
since	O
been	O
reused	O
for	O
various	O
other	O
"	O
accelerating	O
"	O
software	O
products	O
.	O
</s>
