Since a few days I have a problem with my computer. Sometimes the hard drive just doesn't start. Computer goes past all the BIOS screens, then goes to a black screen with just a blinking underscore cursor on the top left corner, and never arrives at the Windows XP boot screen. Hard drive LED remains black. Turn off and on again once or twice, and the computer finally finds the hard drive and boots up normally. I'd replace the hard drive, but I'm not 100% sure that it is really a drive hardware failure. I recently replaced a keyboard which was using the keyboard socket with a new keyboard which uses a USB socket. As I remember having had problems with booting when the keyboard wasn't well connected, I wonder if that could be the problem? Or could it be a BIOS problem? As the error occurs infrequently and not repeatable up to now, it is hard to diagnose. Any advice?