I am running an AMD 64Bit single core processor on a Biostar NF61S Motherboard with 2 GB of RAM with a Radeon Graphics Card.I am currently running PCLinux 32Bit OS,but other OS's have had the same problem including Windows on this computer.When I clear the Bios chip on the Motherboard and restart the Hard drive is found again but the Operating system cannot be repaired,so I have to reinstall the OS but it isnt long before the same problem reappears!Is this likely to be a Hardware problem?and what component may be causing it? Michael NB I have done a Memory test which shows up as OK,also tested the Western Digital SATA Hard drive which shows no bad sectors and healthy.