I have to hard drives on my computer one is fr 300 GB n the other is for 500 GB and both were been detected never had problem in last 8 mnths , but for last 3 days my computer does not detect the 500GB hard drive. Aticipating fr your response.
Did the computer suffer any shocks, BIOS meddling or anything out of normal use ? If still under warranty, I'd have the mfg. repair shop look it over, they can open it without invalidating warranty and check loose wires.