Vista works in the same way as XP did... In other words it sends DRM information back over the net during installation. If you've been using the system for more than 30 days then you will have had to send this DRM info back to MS. This info contains things like CPU, mobo type, chipset, GFX card info to MS in order to prevent illegal installations. Therefore locking the CD key to that particular hardware setup.
I'm afraid you're outta luck there m8.