The only 64 bit OS I have is Vista but I'm going to upgrade that system to Win7 soon. Keeping that in mind:
Which BOINC projects are you talking about? I think many of them still send a 32 bit program regardless of if the machine is 32 or 64 bit. I think some projects only have 64 bit available as an optimized app that you have to download and put in the project directory along with an app_info.xml file.
For that matter, isn't Microsoft Office still 32 bit only?
For Milkyway, there's an optimized app for win64_SSE3 which any Intel Core 2 or later should run on 64 bit windows.
http://www.arkayn.us/milkyway/index.htmlhttp://www.arkayn.us/milkyway/Win64_0.20_SSE3.zipIt may also matter which version of BOINC you're running. The latest version that I haven't had problems with is 6.10.29... Several versions in the 6.10.x series have had various problems including work fetch related problems. There have also been some
OLD bugs that have been discovered and fixed.