Reinstalling Office 97/ Office 2000

I support two platforms, Office 97 and Office 2000.
After installing Office 2000 on several machines, I needed to put Access 97 back.
When I did, I got a message stating not a licensed copy.
I even uninstalled Office 2000 and reinstalled Office 97. I now cannot get Access 97 to work on any machine that Office 2000 was installed.

Is there a solution to this problem? I would appreciate any help. I need to continue to use Office 97 for several applications.

Thank You