Microsoft has confirmed this problem.
This symptom is due to the non-existence of the necessary files to execute the uninstallation.
To resolve this symptom, refer to the procedure below:
-- Procedure --
1. Create a restore point after you have installed Office 97.
2. Click [Start] -> [Settings] -> [Control Panel] -> [Add/Remove Programs] and uninstall [Microsoft Office 2000].
3. Click [Start] -> [Programs] -> [Accessories] -> [System Tools] -> [System Restore] and select [Restore my computer to an earlier time]. Then, choose the restore point you have created in step 1.
4. Re-install Office 97.