I installed a trial version of Outlook 2007 and then purchased the hard copy
of it. I installed it and it never got rid of the trial version. I
uninstalled the new version and went into the trial version and figured that
I could just enter the product key. They say the product key is invalid.
Probably because I already entered it once.

How do I get the product key re-activated? I purchased the product and my
trial version ends tomorrow. 1/31/2009.