Dear Macheads, My HD is fried. My iMac will not start as of yesterday. It got to the loading screen then shut itself off. I tried booting into into safe mode, but that didnt work. When i watched the activity in safe mode it says there was a "Disk I/O Error" then it kills all programs and shuts down. I tried resetting the PRAM and the SMU, but that did nothing. I now have my start up disk in, and ive gone into disk utilities to verify/repair the disk. When I verify the disk it says "Invalid node structure The volume needs to be repaired Error: The underlying task reported failure on exit 1 HFS volume checked Volume needs repair" So i attempt to repair the disk and it says "Invalid sibling link Volume check failed.... ... 1 Volume could not be repaired because of an error" WHAT SHOULD I DO!?! Does this mean I should archive and install? Is there any possibility I can back up a large sum of my data before hand? If I archive and install how much data will I lose? Thank you very much for the help.