Reinstall Office 2008 / Change Office 2008 Serial
Go to your Spotlight search bar and type in “Terminal”
Once that opens copy the following text and paste it into the terminal and press enter:
rm -rf ~/Library/Preferences/Microsoft/Office 2008/Microsoft Office 2008 Settings.plist ; rm-rf /Applications/Microsoft Office 2008/Office/OfficePID.plist
This will remove the serial number and you will be prompted for a new serial number when you open any Office product.