My mac pro is only displaying the Windows XP Drive everytime I hold down the option key, it's the only choice available now. It also only boot into Windows even if I don't have option key hold down. I try taking out the Hard Drive that contain Windows XP and now all I get is a gray screen. It is possible that I hold down the option key too much to boot into Windows XP all the time that the boot rom is broken? I have try all possible ways but all hope is lost at this point. Any help would be greatly appreciated. Here is what I have done. - Re - Install Mac OS X Archieve and Install - Re - Install Mac OS X Upgrade Option - Repaired Disk (No problem founds_ - Repaired Permission - ZAP PRam The only option I havent try is Deleting the Hard Drive and Re-Installing Mac OS X. But I don't want to do that if it doesn't solved the problem. Since I re-install Mac OS X and it still won't bootup. Do you guys think this is my Mac Pro Hardware problem or something with the Hard Drive? It's strange, I think it's Karma because I alway boot into Windows, now my Mac Pro only boot into Windows.