Windows

This issue may occur if one or more of the following files are missing or damaged:
Config.nt
Autoexec.nt
Command.com
RESOLUTION
To resolve this issue:
Click Start, and then click Run.
In the Open box, type cmd, and then click OK.
At the command prompt, type the following commands, pressing ENTER after each command:


expand CD-ROM Drive Letter:\i386\config.nt_ c:\windows\system32\config.nt
expand CD-ROM Drive Letter:\i386\autoexec.nt_ c:\windows\system32\autoexec.nt
expand CD-ROM Drive Letter:\i386\command.co_ c:\windows\system32\command.com
exit

Start or install the program. If the issue is resolved, do not complete the remaining steps. If the issue is not resolved, go to the next step.
Note: The Command.com file is not edited or created in this in the following process. Because of this, you may have to expand it from your Windows XP CD-ROM.

Start Notepad.
In Notepad, type the following entries: dos=high, umb
device=%SYSTEMROOT%\system32\himem.sys
files=40
On the File menu, click Save As.
In the File Name box, type Config.nt, and then click Save. Close the Config.nt file.
On the File menu, click New.
In the new blank document, type the following entries: @echo off
lh %SYSTEMROOT%\system32\mscdexnt.exe
lh %SYSTEMROOT%\system32\redir
lh %SYSTEMROOT%\system32\dosx
SET BLASTER=A220 I5 D1 P330 T3
On the File menu, click Save As.
In the File Name box, type Autoexec.nt, and then click Save. Close the Autoexec.nt file.
Start Windows Explorer. Locate the Config.nt file, right-click the Config.nt file, and then click Copy.
Right-click the %SYSTEMROOT%\System32 folder, and then click Paste.
Locate the Autoexec.nt file, right-click the Autoexec.nt file, and then click Copy.
Right-click the %SYSTEMROOT%\System32 folder, and then click Paste.
Locate the Command.com file, right-click the expanded Command.com file, and then click Copy.
Right-click the %SYSTEMROOT%\System32 folder, and then click Paste. Restart your

Test the NTVDM (Windows Virtual DOS Machine) subsystem:
1. Start / Run / Command.com / OK.
2. If a C:\Windows\System32\Command.com session does NOT open, the NTVDM is misconfigured. Check the Config.nt and Autoexec.nt files in the %SystemRoot%\System32 folder for non-standard entries:

Config.nt
---------

REM Windows MS-DOS Startup File
REM
REM CONFIG.SYS vs CONFIG.NT
REM CONFIG.SYS is not used to initialize the MS-DOS environment.
REM CONFIG.NT is used to initialize the MS-DOS environment unless a
REM different startup file is specified in an application's PIF.
REM
REM ECHOCONFIG
REM By default, no information is displayed when the MS-DOS environment
REM is initialized. To display CONFIG.NT/AUTOEXEC.NT information, add
REM the command echoconfig to CONFIG.NT or other startup file.
REM
REM NTCMDPROMPT
REM When you return to the command prompt from a TSR or while running an
REM MS-DOS-based application, Windows runs COMMAND.COM. This allows the
REM TSR to remain active. To run CMD.EXE, the Windows command prompt,
REM rather than COMMAND.COM, add the command ntcmdprompt to CONFIG.NT or
REM other startup file.
REM
REM DOSONLY
REM By default, you can start any type of application when running
REM COMMAND.COM. If you start an application other than an MS-DOS-based
REM application, any running TSR may be disrupted. To ensure that only
REM MS-DOS-based applications can be started, add the command dosonly to
REM CONFIG.NT or other startup file.
REM
REM EMM
REM You can use EMM command line to configure EMM(Expanded Memory Manager).
REM The syntax is:
REM
REM EMM = [A=AltRegSets] [RAM]
REM

This could be relevant to your issue:
http://support.microsoft.com/default.aspx?scid=kb;en-us;324767

I just ran into the same problem last week. It was easily fixed by copying AUTOEXEC.NT from \Windows\repair to \Windows\System32, but the real problem was spyware. This particular machine had a TON of junk on it, the user mentioned clicking yes in a popup to take a presidential poll and that's when the problem started. I ran Spybot and Ad-Aware SE (I couldn't even download Adaware until I terminated one of the rogue processes. The download was sitting there doing nothing, as soon as I terminated the process it started right up) and still had to do some manual removal of some startup processes, really nasty stuff.

This issue may occur if one or more of the following files are missing or damaged:
Config.nt
Autoexec.nt
Command.com
RESOLUTION
To resolve this issue:
Click Start, and then click Run.
In the Open box, type cmd, and then click OK.
At the command prompt, type the following commands, pressing ENTER after each command:


expand CD-ROM Drive Letter:\i386\config.nt_ c:\windows\system32\config.nt
expand CD-ROM Drive Letter:\i386\autoexec.nt_ c:\windows\system32\autoexec.nt
expand CD-ROM Drive Letter:\i386\command.co_ c:\windows\system32\command.com
exit