Okay, so it seems that many of the rumours floating around about some of the new stipulations in the Windows Vsta EULA were nothing more than FUD. Originally everybody believed that your copy of Vista would allow you to upgrade your PC (i.e. swap the motherboard) once. Period. Apparently MS just released a statement that debunked that belief. A Microsoft spokesperson told bit-tech that the only upgrades that will force you to reactivate your copy of Vista would be those involving the hard drive and one other component. Anything else (video card, sound card, memory, CPU, PPU, whatever) would not require reactivation. Also, apparently you are allowed to reactivate *ten* times, not once like previously believed. Once your ten activations are up, you can call Microsoft as always and they will give you a new activation code if they don't think you're running multiple machines under the same key. Generally in my experience they just give you a code without any questions so long as your current key is not blacklisted. If they do, most likely the worst case scenario is they will ask you where you obtained your copy, and so long as your answer is not "The interweb" they will generally give you a new license for free if you narc on whoever provided you the pirated copy.
My question is what happens if you upgrade your video card and then add a supplementary hard drive? Will it be the case where as long as that original hard drive you installed Vista on in the first place is present, it won't make you reactivate? I'm sure that is probably the case, but I'm not certain. It will be interesting to see what happens to people who are running multiple hard drives, especially externals and hot-swappables. I am confident that Microsoft has though of this, though.