Here is my problem: I bought an iMac December 2009. When I first got my iMac, I used Bootcamp to install Windows XP. It all worked fine. Then I decided that I want to REMOVE Windows XP and put Windows 7 instead. So what I did is tell Bootcamp to first remove my Windows partition. It worked perfectly fine with no errors whatsoever. Then when I tried to re-create the Windows partition, it told me it had failed to move files (pretty common error). So I've done my researches. And I followed what some people said: iDefrag. I created the live CD, defragmented my Mac partition using compact algorithm. Defragmentation went great. Rebooted. Started Bootcamp, but same error. Restarted in "Safe Mode", Bootcamp gives the same error. So, I've done my researches again and found out I could do this: Boot off my Mac Installation Snow Leopard disk Use Disk utility to resize my Mac partition to a smaller one and create a free space Expand my Mac partition again into one single partition Bootcamp should work... Now I wanted to do this but when I restarted my iMac with the Installation disk on, it asked for language and then I saw "Preparing for Installation" loading bar. Of course, scared that it will re-install Mac OS, I forcibly shut downed my Mac. Now, my questions are: How do I boot from an installation Mac disk JUST to use Disk Utility? Resizing the Mac partition to a smaller one then expanding it: will that really work? Any other suggestion to fix that Bootcamp error? Honestly, I know I could save myself from all the hassle and just reformat my thing and reinstall Mac, but, I have no external hard drives to backup all my data files. Will creating a new Mac partition and moving my important stuff on that partition, then formatting the partition with the Mac OS installed on it and re-installing the Mac OS will make Bootcamp work properly? Any help would be REALLY REALLY appreciated.