Fixes for blinking folder with ? mark?

I really don't know what else to try. I've tried pressing the Options button when I heard the chime (Which only worked once recently), I've tried inserting the disc which came with the computer and going into Disk Utilities, but the Repair Disk option is greyed out. When I press Verify Disk Permissions, I get an error saying No valid packages, although I've never deleted anything under /Library/Receipts. I've also tried re-installing the software using the disc, but the farthest I can go is Destinations, which is just a blank page. I also tried using the Safe Boot command, but nothing worked. Anyone have any idea on how I can fix this problem without a risk of losing data?