<s>
WinDbg	B-Application
is	O
a	O
multipurpose	O
debugger	B-Application
for	O
the	O
Microsoft	B-Application
Windows	I-Application
computer	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
,	O
distributed	O
by	O
Microsoft	O
.	O
</s>
<s>
It	O
can	O
be	O
used	O
to	O
debug	O
user	B-Operating_System
mode	I-Operating_System
applications	O
,	O
device	B-Application
drivers	I-Application
,	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
itself	O
in	O
kernel	O
mode	O
.	O
</s>
<s>
Like	O
the	O
better-known	O
Visual	O
Studio	O
Debugger	B-Application
WinDbg	B-Application
has	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
,	O
but	O
is	O
more	O
powerful	O
and	O
has	O
little	O
else	O
in	O
common	O
.	O
</s>
<s>
WinDbg	B-Application
can	O
automatically	O
load	O
debugging	O
symbol	O
files	O
(	O
e.g.	O
,	O
PDB	O
files	O
)	O
from	O
a	O
server	O
by	O
matching	O
various	O
criteria	O
(	O
e.g.	O
,	O
timestamp	O
,	O
CRC	O
,	O
single	O
or	O
multiprocessor	O
version	O
)	O
via	O
SymSrv	O
(	O
SymSrv.dll	O
)	O
,	O
instead	O
of	O
the	O
more	O
time-consuming	O
task	O
of	O
creating	O
a	O
symbol	O
tree	O
for	O
a	O
debugging	O
target	O
environment	O
.	O
</s>
<s>
WinDbg	B-Application
can	O
also	O
be	O
used	O
for	O
debugging	O
kernel-mode	O
memory	B-Error_Name
dumps	I-Error_Name
,	O
created	O
after	O
what	O
is	O
commonly	O
called	O
the	O
Blue	O
Screen	O
of	O
Death	O
which	O
occurs	O
when	O
a	O
bug	B-Error_Name
check	I-Error_Name
is	O
issued	O
.	O
</s>
<s>
It	O
can	O
also	O
be	O
used	O
to	O
debug	O
user-mode	O
crash	B-Error_Name
dumps	I-Error_Name
.	O
</s>
<s>
Recent	O
versions	O
of	O
WinDbg	B-Application
have	O
been	O
and	O
are	O
being	O
distributed	O
as	O
part	O
of	O
the	O
free	O
Debugging	B-Application
Tools	I-Application
for	O
Windows	O
suite	O
,	O
which	O
shares	O
a	O
common	O
debugging	O
back-end	B-Architecture
between	O
WinDbg	B-Application
and	O
command	B-Application
line	I-Application
debugger	B-Application
front-ends	B-Architecture
like	O
KD	O
,	O
CDB	O
,	O
and	O
NTSD	O
.	O
</s>
<s>
Most	O
commands	O
can	O
be	O
used	O
as	O
is	O
with	O
all	O
the	O
included	O
debugger	B-Application
front-ends	B-Architecture
.	O
</s>
<s>
In	O
2017	O
Microsoft	O
announced	O
new	O
version	O
of	O
WinDbg	B-Application
called	O
WinDbg	B-Application
Preview	O
(	O
aka	O
WinDbgX	O
)	O
.	O
</s>
<s>
One	O
of	O
the	O
most	O
notable	O
features	O
of	O
WinDbg	B-Application
Preview	O
is	O
so	O
called	O
Time-Travel-Debugging	B-Application
(	O
TTD	O
)	O
.	O
</s>
<s>
WinDbg	B-Application
allows	O
the	O
loading	O
of	O
extension	O
DLLs	O
that	O
can	O
augment	O
the	O
debugger	B-Application
's	O
supported	O
commands	O
and	O
allow	O
for	O
help	O
in	O
debugging	O
specific	O
scenarios	O
:	O
for	O
example	O
,	O
displaying	O
an	O
MSXML	B-Application
document	O
given	O
an	O
IXMLDOMDocument	O
,	O
or	O
debugging	O
the	O
Common	O
Language	O
Runtime	O
(	O
CLR	O
)	O
.	O
</s>
<s>
These	O
extensions	O
are	O
a	O
large	O
part	O
of	O
what	O
makes	O
WinDbg	B-Application
such	O
a	O
powerful	O
debugger	B-Application
.	O
</s>
<s>
WinDbg	B-Application
is	O
used	O
by	O
the	O
Microsoft	B-Application
Windows	I-Application
product	O
team	O
to	O
build	O
Windows	O
,	O
and	O
everything	O
needed	O
to	O
debug	O
Windows	O
is	O
included	O
in	O
these	O
extension	O
DLLs	O
.	O
</s>
<s>
While	O
some	O
extensions	O
are	O
used	O
only	O
inside	O
Microsoft	O
,	O
most	O
of	O
them	O
are	O
part	O
of	O
the	O
public	O
Debugging	B-Application
Tools	I-Application
for	O
Windows	O
package	O
.	O
</s>
<s>
The	O
extension	O
model	O
is	O
documented	O
in	O
the	O
help	O
file	O
included	O
with	O
the	O
Debugging	B-Application
Tools	I-Application
for	O
Windows	O
.	O
</s>
<s>
Ext	O
is	O
a	O
standard	O
Windows	O
Debugger	B-Application
extension	O
that	O
ships	O
with	O
WinDBG	B-Application
and	O
is	O
loaded	O
by	O
default	O
.	O
</s>
<s>
Wow6432exts	O
is	O
a	O
standard	O
Windows	O
Debugger	B-Application
extension	O
that	O
ships	O
with	O
WinDBG	B-Application
.	O
</s>
<s>
It	O
is	O
used	O
to	O
debug	O
processes	O
running	O
inside	O
WoW64	B-Application
(	O
32-bit	O
processes	O
running	O
in	O
64-bit	O
Windows	O
)	O
.	O
</s>
<s>
The	O
SOS	O
(	O
Son	O
of	O
Strike	O
)	O
Debugging	O
Extension	O
(	O
SOS.dll	O
)	O
assists	O
in	O
debugging	O
managed	O
programs	O
in	O
Visual	O
Studio	O
and	O
WinDbg	B-Application
by	O
providing	O
information	O
about	O
the	O
internal	O
common	O
language	O
runtime	O
(	O
CLR	O
)	O
environment	O
.	O
</s>
<s>
To	O
debug	O
a	O
process	O
or	O
memory	B-Error_Name
dump	I-Error_Name
,	O
the	O
sos.dll	O
version	O
must	O
match	O
the	O
.NET	O
Framework	O
version	O
.	O
</s>
<s>
Psscor2	O
is	O
the	O
Windows	O
Debugger	B-Application
Extension	O
used	O
to	O
debug	O
.NET	O
Framework	O
applications	O
that	O
use	O
the	O
.NET	O
CLR	O
version	O
2.0	O
(	O
.NET	O
Framework	O
versions	O
2	O
through	O
3.5	O
)	O
.	O
</s>
<s>
Psscor4	O
is	O
a	O
Windows	O
Debugger	B-Application
extension	O
used	O
to	O
debug	O
.NET	O
Framework	O
4	O
applications	O
.	O
</s>
<s>
WinDbg	B-Application
allows	O
debugging	O
a	O
Microsoft	B-Application
Windows	I-Application
kernel	O
running	O
on	O
a	O
virtual	B-Architecture
machine	I-Architecture
by	O
VMware	O
,	O
VPC	B-Application
or	O
Parallels	O
using	O
a	O
named	B-Operating_System
pipe	I-Operating_System
.	O
</s>
<s>
This	O
can	O
be	O
achieved	O
by	O
using	O
a	O
virtual	B-Application
COM	B-Architecture
port	I-Architecture
.	O
</s>
<s>
In	O
the	O
case	O
of	O
VMware	O
and	O
VirtualBox	B-Operating_System
,	O
the	O
VirtualKD	O
extension	O
adds	O
native	O
support	O
for	O
VM	O
debugging	O
to	O
the	O
Windows	O
kernel	O
,	O
claiming	O
to	O
speed	O
debugging	O
by	O
a	O
factor	O
of	O
up	O
to	O
45	O
.	O
</s>
<s>
For	O
Windows	B-Application
8	I-Application
and	O
later	O
,	O
kernel	O
debugging	O
over	O
network	O
is	O
allowed	O
,	O
allowing	O
fast	O
kernel	O
debugging	O
without	O
special	O
configuration	O
.	O
</s>
<s>
The	O
WinDbg	B-Application
protocol	O
is	O
not	O
documented	O
,	O
but	O
is	O
supported	O
by	O
the	O
IDA	B-Application
Pro	I-Application
and	O
radare2	B-Language
disassemblers	O
.	O
</s>
