I have a troubling scenario that I can not seem to remedy, and I would appreciate help if anyone has seen this before:

I have a client with a machine that has VFP5 installed. My company has developed an application for this client in VFP6. So while at the client site, I installed VFP6 on the same machine for testing & debugging purposes. I then applied Service Pack 3 for VFP6/Visual Studio. Everything was fine; VFP5 ran properly as well as VFP6.

Then, several days ago I got a call from the client saying that the application we developed had stopped running properly. Errors were appearing like "newobject.prg not found" or messages to the effect that VARTYPE() was not a function. Obviously, I assumed that they were trying to run the code using VFP5 (they are starting the application through the command window, do main.prg). But they aren't. I called up, made sure we were using VFP6, and ran the code; and sure enough the errors would come up. But if I took the same line that caused the error & pasted it into the command window, it worked fine!

After doing some investigation, it turns out that someone installed Visual Studio 97 (!) Service Pack 3 on that computer right before the errors started appearing. Obviously, this has messed something up; now VFP6 seems to want to use the VFP5 runtimes...Can anyone tell me how to fix this problem short of uninstalling everything and starting over or re-installing Windows NT?

Any help will be greatly appreciated. Thank you.