Application error NTVDM.EXE (Q165404)

I have a pc installed with Windows NT SP4.

Suddenly I receive the following error message:
NTVDM.EXE application error.

Error the instruction 0x0f046fa, the memory could not be read.
(Everything can be seen in Q165404 from technet).

The sollution would be to reinstall or install service pack 4. We did this, but no help. Problem still persists.
Everytime in a certain program, bang.. application error.

It's not alloud to install a higher service pack then 4, so I hope there are some other things to do.

LEt me know, thanks.

Never mind.. Already reinstalled O.S.