I see the other thread on here, but it didn't help me. Okay, so I have a black Intel-based Macbook that had OS X on it. I booted with Windows XP install disc and installed Windows over the entire HD. Everything worked fine, windows ran, but I didn't realize how foolish it is to erase OS X until it was too late. I'm trying to install the Mac OS again. When I try to boot from "Mac OS X Install Disc 1" - either by holding down 'c' during startup or holding down option and clicking on the DVD - it brings up a gray screen with the Apple logo and then restarts the computer after a few seconds. It is the DVD that came with my macbook. The computer will boot to the Windows XP cd - I used it to remove the NTFS partition with windows and create a new partition and formatted it as FAT. The same thing happens when I try to boot from the OS X DVD. I've tried to boot Knoppix in order to format the partition to hfs or hfs+ but I can't get Knoppix CD to boot either. I've tried every combination of "holding down keys during booting" with an unpartitioned drive, with a 20GB FAT partition, with a 20GB FAT32 partition, etc. I've tried everything I can think of or find on this forum or on any other forum. Any help would be greatly appreciated - thanks so much! By the way, I have another Macbook but no firewire cable. I've checked the OS X install DVD on other macbooks and it's totally mint, perfect working order. It's totally blowing my mind how this new apple macbook is booting off the Windows XP install disc but not off its OWN install disc.