For what it's worth, I recently loaded my BIAB Windows 2007 Megapack on an iMac that has a 32 bit Windows 7 Professional Bootcamp partition. It seems to run OK, but I do get a crash error every time I close the program. As I said, it's running on a Mac, but presumably it shouldn't really be any different at this point than if it were a PC. I have not spent the time to reinstall the program to see if that helps.