I have a Clipper program that runs fine on a Pentium 133, 330MB RAM Compaq Proliant 2000 under Win 2K Pro and Win 2K Server (dual boot). I can run multiple instances of the program when using a shortcut configured to use no EMS memory even though the executable is 900KB. And I can also run the program using the DOS command prompt window.

The program runs fine on a Dual Pentium 133, 130MB RAM HP NetServer LH+ under Win NT4 Server using both a shortcut and from a DOS Prompt.

It also works fine on my TI Extensa 510 PI 100MHZ, 16MB RAM laptop under Win 95.

Here's the problem. I can't run the exact same program on an IBM Thinkpad T20 PIII 750MHZ, 256MB RAM under Win 2K Pro, a Dell Optiplex PIII 833MHZ, 256MB RAM under Win 2K Pro, an HP NetServer LC3 dual PIII 600MHZ, 450MB RAM under Win NT 4 Server. All that happens when running from a shortcut; a DOS window pops up with "Inactive program name" in the title bar. When run from the DOS Prompt, nothing happens and I end up with the "C:\>" prompt.

Microsoft Technet (http://support.microsoft.com/support/kb/articles/Q196/4/53.ASP), "Troubleshooting NTVDM and WOW Startup Errors" says that there seems to be a problem running DOS applications when upgrading from a previous Windows OS to NT 4 or 2000. I can run sysedit from the DOS prompt which means that the above exe and dll's are fine. I've copied over the recommended ini files from the Win 2K CD, checked the registry parameters and the environmental variables (as they suggest this is possibly the culprit) but everything is in order. Autoexec.nt and Config.nt were stripped to bare essentials as well. The shortcut was configured multiple times to use different EMS, XMS memory to no avail.

Still the program won't run on the PIII's. Does anyone know whether or not this is an Intel chip problem? I can't perform fresh re-installs of Win 2K on these machines as they aren't mine... the two older Pentium I servers are but that doesn't help because the program runs fine on them.

Any help would be greatly appreciated.