I recently activated my Microsoft Office 2010 over the phone (as the product key kept saying it wasn't valid) and it said that it was successful. But every time I get into Word, Excel...etc it says that my product key is still not valid and wants me to try and activate it again via the internet.

So my question is: How do I activate it?

From Fustrated

This guided troubleshooter may be helpful:
http://support2.microsoft.com/common/survey.aspx?scid=sw;en;1844&showpage=1

Alternatively, you can contact MSFT telephone activation again, but, when the Automated Telephone System answers your call, do not respond, and you will be connected with a person (not a machine) to who you can explain, and who can help you.