One of the machines I'm migrating is a Windows 2003 Server (Enterprise Edition) and its running on MS Virtual PC 2007 at the moment. But when I use the VMWare migration tool to make it a VMWare image the OS needs to be re-activated (as the VMWare virtual hardware is different to MS Virtual PC).
Sadly work doesn't want to spring for a licence for me to do this so I need to... find another solution to the problem

Anyone have any of the "other solutions" I might be after?
I'm rather strongly against a complete re-install of the OS (ie, trashing the machine) as there is stuff installed that I don't want to have to re-install (and thus re-activate anyway!).