Not sure. I got the iMac with OS 10, Parallels, and XP preinstalled. I then upgraded to 3212 and I'm not sure if I can get back to 3188 without creating more problems than I have now. I'm hoping for a solution to come from an upcoming Parallels patch to fix some USB problems (noted in a different thread) or an upgrade to 10.4.10. This may be wishful thinking and I may have to bite the bullet and uninstall 3312 and attempt to reinstall 3188.