I have a macpro with OSX on one drive and windows 7 on a partition of another drive. Both systems work fine and I boot into windows by holding the option key down. What is odd is if I go to the system preferences startup disk my windows install does not show up. I did move my windows partition a while ago to a new drive. I used bootcamp to create the partition and winclone to move the data. It's not a big deal not having the option in the preference pain but would be nice. If I am in windows and go to the bootcamp control panel both OS X and Windows are there.