In Windows XP you were allowed to move the copy of Windows XP between one computer at a time. Making sure XP was only allowed to be installed on one PC at any one time.

Microsoft have tweaked the Windows Vista license as follows. You can move the copy between PC’s, but only once.

This is bad take this example.

You purchase Windows Vista for an old PC.
You install and activate it, run it for a bit and decide the old PC cant really run Windows Vista all that well so you install Windows Vista on a new PC.

Thats it, you will not be able to transfer the Windows Vista PC to any other PC without first contacting Microsoft and making a case for reinstalling yet again.

Chances are they will say yes, but they don’t have too.

Link: http://blogs.zdnet.com/Bott/?p=156

Update: Paul Thurrott says its only slightly worse than the Windows XP rights, but worse is still worse.

Link: http://www.winsupersite.com/showcase/winvista_licensing.asp