I have a 24" 2.8GHz iMac that seems to be working just fine. However I decided to run some of the first aid stuff on the hd and when I asked it to verify the disk it came up with a prompt that states "This disk needs to be repaired. Start up your computer with another disk(such as your Mac OS X installation disc). And then use disk utility to repair this disk." So now my question is, is that I don't have access to the original discs at the time so what should I do? I currently have a 500gb mybook connected with time machine backups current and a FireWire 400 external with little to nothing on it as well. Is there a way to repair whatever needs to be repaired without the original discs? I'm sure I could get them as they are just in storage in the original box but it would be much much nicer if I didn't need to.