It actually sounds like your harddrive has crashed its Master Boot Record. It is possible to use a Knoppix Live CD and perform repairs to the MBR It is complicated and you will need to study up on how to.....

But first I would try this...pull out your harddrive and record the type and manufacturer/model...then go to the hdd manufactures website and look for the repair/installation utillity download. It should fit on a Floppy or CD either one...(follow download/installation proceedures). Boot to that utillity and have it run diagnostics and repair options for that drive! It maybe possible for the repair option (Chkdisc) to find the errors and repair the problem.

Good luck!