I think the question says it all bu I am uprading my old XP workgroup which currently has 7 PC on it. So far I have updated 3 machines with W7 32 bit and they all wqrk fine. Howeve one of he machines is used much harder than the others so I was wondering if it is worth updating that one with W7 64 bit (the machine is 64 bit ready) I would also then be able to use all the memory which is installed. Is it a good idea or even possible to mix on the same workgroup? - I will need to keep the workgroup in place as I will still have two XP machines which are needed for software compatibility reasons.