Downgrading from Windows Vista 64 bit to 32 bit with your upgrade disk
Most users who installed 64 bit copies of vista than decided it wasn’t for them for one reason or another found that they had product key problems once they wanted to re-install vista 32 bit using thier upgrade disk. Most would have to install windows Xp then run the upgrade again, but here’s a nice work-around to that problem.
Run your vista 32 bit install and skip the part where it asks for a product key, DON’T EVEN TRY TO ENTER A KEY you’ll just get errors. Once you boot up into Vista for the first time, just insert the CD/DVD again and then choose to