I currently run an AMD 6400+ Black Edition Processor and 4Gb of RAM and the 64bit versions of Vista Ultimate and Maya 2008.
The only word of caution I would give is to turn off the Aero UI in Vista, and go to classic mode as it can cause issues with the viewports. Plus Vista runs faster without it and you'll not use it after a while...
GL
Chris (formerly R@nSiD)
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When the power of love overcomes the love of power the world will truely know peace - Jimmy Hendrix
Winner SM VFX Challenge 1
3rd Place SM SteamPunk Challenge (May 2007)