there is nothing wrong with Vista x64 drivers. You can find them everywhere, so no worries there. There used to be a problem about 6-10 months back when they were scarse, but microsoft has done a good job of getting everything done in x64 bit along with x86 bit.
Overall though, you are going to see a knoticable decrease in FPS on a machine with vista, everything works...but not like it used to on XP.
If your making a gaming machine go with XP, other than that, it honestly doesnt matter.
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