Ok, my friend's having trouble with Bios not recognizing his hard drive. He has plugged in a new sata cable and sata power cable, but still no luck. Here's what he had to say: "My hard drive was running low on space so it was running slow.. thats when i thought to delete some stuff and i freed up 5 gigs.. and it seemed to be faster.. then all of the sudden, it rebooted by itself.. and it won't boot up again... and bios doesnt recognize the hard drive." The specs he gave me of his computer are: Motherboard - Asus P4C800-E CPU - Pentium 4, 2.6 GHZ Memory - 1 GB DDR400 Hard Drive - Seagate 80GB Sata Video Card - ATI Radeon 9600XT 128MB Is there anyway to possibly fix this error so he still has his stuff on his hard drive or at least still be able to use it?

Ive had this problem, dont remember the solution. But try hooking it up to another computer and see if that computer can read the HD

The Asus P4C800-E has an option to enable/disable the SATA integrated controller. In fact, there may be a setting in the BIOS software as well as the jumper on the motherboard. If either one of these has been disabled, the BIOS won't see the SATA drive(s). If you reset the factory default on your motherboard, I'm pretty sure ASUS does not include SATA-enabled as part of the default. Other possibilties are that the power lead which attaches to the SATA drive is not securely in place, or that the data cable (4 wire lead) has been detached at either the motherboard interface, or at the drive itself. Double check the cables, as they gave me a hard time the first time I tried to install a SATA drive. I was not blessed with ballerina fingers. Cabling can really be a pain, especially if you're using lots of bays for your drives. Healthy ventilation requires that you leave space between the drives, but that's exactly the condition that can stretch the cables to their absolute limits. Don't skimp on length: http://www.cablesnmor.com/index.asp?PageAction=VIEWCATS&Category=249 Beauty of the high sierra, and she's looking out for you.

He already thought of doing that but his brothers computer doesn't support SATA HDs.

If you are right Dr. Zhivago, what would explain the computer resetting itself and not be able to boot up right again?