License question about upgrading to office 2003

[ReddMurphy]

I have a full version of Ofice 2000 Pofessional, and I still have the original cds and key. I just bought a new computer and an upgrade version of Ofice 2003 Basic. The new machine came with the trial version of Office 2003 (not sure of the version) already installed on the machine. Obviously, my goal is to just have a licensed version of 2003 on my machine.

Do I have to uninstall the trial version of 2003, install the 2000 version, and then install the upgrade? It seems like a lot of work to install software that's already on the machine. Is it possible to call Microsoft and give them the necessary product keys and have them give me a key to use the installed software?

Thanks in advance.