When you try to use Control Panel / Add/Remove Programs, you receive:
Another Installation is already in progress. Complete that installation before proceeding with this install.
This can occur if you upgraded a W9x computer to Windows 2000 and Office 2000 was installed prior to the upgrade.
To resolve the issue:
1. Close Add/Remove Programs and Control Panel.
2. Restart Windows 2000.
3. Control Panel / Add/Remove Programs.
4. Uninstall Microsoft Office 2000.
5. You may need to manually delete the Office 2000 icons from the Programs menu and Startup folder.
6. Restart Windows 2000.
7. Install Office 2000.