How can I check whether a Microsoft Office 2003 has been used (license activated) already?

I have a copy of Microsoft Office Professional Edition 2003, but I don't know if it's been activated/used. How can I check to see before I sell it?

How can I check whether a Microsoft Office 2003 has been used (license activated) already?
Call Microsoft. http://www.microsoft.com/piracy/mpa.aspx
Reply:go to the Microsoft web site and try to download some kind of spy-ware protection for your pc and it will tell you if your installed Microsoft software is licensed and authentic..