If your program is installed in c:\Program Files that would explain a lot. You should not have modifiable data files installed under \Program Files or you may end up with curious results. Other than that I haven't had any difficulty with Win7 64 or 32 bit.

>Dear all,
>
>I find that an application developed by XP can smoothly run on a Vista machine but not for Win 7!
>
>
>
>Regards,
>
>Ransome