Okay, I'm about to go crazy over this. I have a 24" mid 2007 iMac; 2.4 C2D. I purchased a legal msdn download of Windows 7 Professional; 64-bit with my education discount. I currently have Windows XP on my bootcamp partition. I knew that I would have to do a clean install, but I've been unable to do anything. First, I burned the ISO onto a dvd using microsoft's utility. When I restarted and booted, it came up with: 1. 2. Select CD-ROM type ...and hangs there. I looked up a lot of stuff, and then burned the ISO in another imaging app. I've tried installing from boot camp setup assistant, booting from the disk, even tried installing inside of VMWare Fusion. Nothing has worked. I would do the USB thumbdrive installation, but from what I understand, the EFI doesn't permit you to boot from USB. Any help would be greatly appreciated. Thanks so much, and Merry Christmas!