This is most likely a PATH related issue. Can you go to Help > About, press the 'Info' button, press the 'Copy all pages' button on this info screen, and paste this text into an e-mail reply?
For the record - this issue was fixed by implementing the fix suggested by Allround. The problem turned out to be a dropped PATH reference to C:\ORACLE\ORA92\BIN. We don't know how it was removed, but adding it back in the "My Computer" Environmental Variables fixed this problem.
Thanks for your excellent support!
WILDMAN