Setup.exe files do not run.

When ever i try to setup any applications my windows 2000 gives me an error saying “c:\winnt\system32\autoexec.nt. The system file is not suitable for running MS-DOS and Microsoft Windows Applications. Choose ‘close’ to terminate the application.”
Where as if the run the same setup file on any other windows 2000 machine it does work fine. The setup.exe file executes.

What could be the problem? DOes anyone know how to resolve this?

Regards,
Sundeep.