i have an ibook g4. i was going to reinstall mac os x so i already put all my documents and such on disk, but after reinstalling the os i find my computer will rarely get past the gray startup screen. when i tried to log in under single mode it said I/O failure...and won't give me a command line so i can't even try fsck... safe mode hasn't worked at all yet, though perhaps i'm not waiting long enough; there's a cd that's in there also, tech tool deluxe. when it actually went to the tech tool the surface scan and volume structure tests failed and i tried to use tech tool to repair them but after it was apparently done it tried to restart it's self and now i'm back to the grey startup screen again.... i've included as many details as possible off the top of my head so maybe someone who knows more about macs will be able to help me, i've never had to fix one before. any and all help would be much appreciated, i'm addicted to photoshop cs and i hate this crappy hp pc i'm now using to cry for help!