i was just wondering if you install a OEM verison of vista home perium and u wanted to reformate computer does that mean the VISTA cd key won;'t work anymore?
The key will work, but you may be prompted to call Microsoft. Usually the key is tied to the mac number of your motherboard, so if you are just reformatting and changing nothing, you should be fine.
If you don't change any of the hardware, you'll be fine.
My Vista machine is on it's third OEM install, and I have had no problems with activation so far... at the worst, you may have to call in to have it re-activated...
I just added a sound card to my Vista x64 system that has been running about 1 month. Did not have to reactivate. I was concerned about adding any new hardware to an existing system, and running into activation issues.
I think Vista's implementation of the activation is a little bit more lenient than XP's. Short of changing the mobo, you can get away with a lot of changes to vista. With XP I triggered an activation with a cdrom change... go figure.