Office 2000 keeps trying to re-install

I installed MS Office to my client computer from my server as an Administrator. Whenever I or any user logs on and tries to run an Office app. it tries to re-install itself. This even occurs after I successfully get into one of the Office apps. The next time I try to open it, it will try to re-install itself.
Please help. My operating systems are Win 2000/XP workstations.