Originally Posted by radekhulan
Unfortunately, Vista cannot be deactivated (like e.g. Adobe products), and activated again. So you will have to call Microsoft hotline, doing phone activation on new PC, and pursade them that it is your only installation.
If you do it 10-times within 1 month, they might object though
I've done it before with XP. I just called them up and explained that I had uninstalled XP completely on the old machine and wanted to install it on just the new machine. Just wanted to make sure it was the same process with Vista.