Ugh! I can't stand Microsoft products personally, but the majority of my customers prefer to use it and since I'm happy to help them out, I run Windows XP over Parallels.
What's really annoying is how hard Microsoft makes it to support the various versions of their software. I'm always amazed at how different the menus are from one version to the next, which makes it nearly impossible to support all their versions.
And the errors you get are so random! I just helped out a customer with the "message stuck in outbox" syndrome. What the? Its was a good challenge, but in the end we manually deleted the outbox.dbx file.