In which Office application you are facing this issue?
what happens if you disable the addins, does the applications work ?
Remove the older version of Office (If installed) using the Fixit tool in the link mentioned below and check if it helps:
http://support.microsoft.com/kb/971179
Note: Ensure you have the disc and the product key for the Office suite to re-install.
Once the previous version is removed, repair the new office and check how it works