Originally Posted by RaidenWoW
I bought my copy of Windows Vista through microsoft's digital locker thing.
I have changed my hardware a few times before and I had to call microsoft and enter in a few numbers to activate my installation again. I assume the same will be true if I just switch to 64-bit (Just say that "this is the only windows copy using this key" and get a code to enter).
Yea you just need to get your hands on a 64-bit version of Vista that matches your type (ie Basic, Home Preimum, Ultimate, etc.)