I'm on 32bit win2k in Parallels, but there is a good reason for it! Half the trouble with 32bit comes from all this old software (sup avisynth) but is only available properly in avs. A side project I have approaches this issue in an interesting way but due to lack of centralised avs plugin building, you can't expect developers to provide 64bit plugins. The same goes for many other common tools, some of them considerably more useful for day to day computing. Compare this to linux where pretty much everything is available in both with the rare exception of pretty much Skype, or on OSX where a few old system apps are 32bit. Windows on the other hand is an almost 40/60 shift, with 32bit taking up the larger chunk. Microsoft really need to just deprecate 32bit and make the OS itself only 64bit. Nobody is running it on hardware old enough for this to be an issue afterall, and you can still have 32bit software in 64bit. It does however go a long way to start resolving the issue.