|Do have a setup file of Microsoft Office? Try uninstalling it and installing it again.|
If not, there should be a repair option in the Control Panel >> Programs >> Uninstall a Program >> Find Microsoft Office and double click it.
If still not available, try system restore to a time when it was last working. Refer here for system restore. http://windows.microsoft.com/en-US/...
NOTE: Doing any of those will not affect your notebook.
Hope that helps. :-)