No Command window will open

[Guest]

When I go to: Start/run and type in cmd the black command window opens for a
split second and vanishes so I cannot type in any commands. What can I do to
fix this problem?

 

[Shenan Stanley]

When I go to: Start/run and type in cmd the black command window
opens for a split second and vanishes so I cannot type in any
commands. What can I do to fix this problem?

Does it work in safe mode?
Does it work as another user on this system?
Are you an administrator?

 

[Guest]

Does it work in safe mode?
Does it work as another user on this system?
Are you an administrator?

I am the administrator on this computer.
It does not seem to work as another user. The command window vanishes after
a split second.
In safe mode the window opens but I then get the following error message:

C:\windows\system32\cmd.com
The NTVDM cpu has encountered an illegal instruction
CS: 0dd9 IP: fff8 OP: d9 0dd9 choose 'close' to
terminate the application

 

[Shenan Stanley]

When I go to: Start/run and type in cmd the black command window
opens for a split second and vanishes so I cannot type in any
commands. What can I do to fix this problem?

Does it work in safe mode?
Does it work as another user on this system?
Are you an administrator?

I am the administrator on this computer.
It does not seem to work as another user. The command window
vanishes after a split second.
In safe mode the window opens but I then get the following error
message:

C:\windows\system32\cmd.com
The NTVDM cpu has encountered an illegal instruction
CS: 0dd9 IP: fff8 OP: d9 0dd9 choose 'close' to
terminate the application

There is a possibility some of your files have been replaced.
Perhaps running a sfc /scannow might help with this.

Otherwise, look here:
http://support.microsoft.com/kb/196453/

And here:
http://support.microsoft.com/kb/245184

Although those are about older products - they may point you into the right
direction.