Hi Denis.

>I try to open _base (checkbox) from "Microsoft visual foxpro 9" and I receive an error message saying that the vct is invalid
>
>I try to open _base (checkbox) from "Microsoft visual foxpro 9 copy" and everything works fine

I'm guessing you're running Vista. The Program Files folder and all subdirectories is read-only in Vista and VFP needs to open classes as read-write. If it can't, it gives that error. Normally Vista's virtualization feature automatically redirect writes to Program Files to a virtualization folder under C:\Users, and it appears to do that for the "copy" folder but not the original VFP folder. I'm not sure why that is, but looking in C:\Users\(your name)\AppData\Local\VirtualStore\Program Files is a start.

Doug