Test all leads that attach to your hard drive including electrical extensions,IDE

the leads from your MOTHERBOARD TO YOUR HARD DRIVE make sure they have a secure dust free connections and are not faulty or just replace them they could be faulty

make sure all leads that are attached to your drives dvd\cd 3 1/2 inch floppy have secure connections and are not faulty even the electrical extensions or just replace them they could be faulty a computer needs its connections to continue its cycle and have an end so any faulty leads will end up with a computer error

even something as small as a faulty electrical extension or fan lead can cause you problems

computers need all of the data and electrical current to travel through every working device and to have an end to be able work properly

motherboard and a hard drive any leads between them will fail before your motherboard or your hard drive if its a flat ribbon 40 pin type IDE replace it this will be the first to fail

check all electrical power input and extensions make sure they are securely seated even the cd/dvd floppy drives need to have current go through make sure these drives are working

hope this helps you