Hi i have a os problem , i recently bought a cc from a jumble sale , and when I turn it on it comes up with a smiley face ,then a floppy symbol with a ? in it . I have tried loading os 7 (which came with my mac classic) and it just spits it out , I've also tried 7.5 and it comes up with " The instaler document "system 7.5 installation" is unusable for installation. A error was detected before installation began. Make sure ouare using the original instaler disks" , any ideas? Help!