Windows Nt Data

Background: I.T. Dept. Network Enginner w/ full domain rights. Windows Nt Server 4.0 sp6a & workstations.

About 3 weeks ago anything program I download from the Internet or ex. copy cd to server will not run the executable. The error I receive is” cannot find .exe” — even though I am clicking on the exe, subsequently when a zip is ran it expands and copies fine to the server disk, but then errors on trying to run the setup.exe

Please Help