Please can anyone help me with this one: My PC's had it and needs a format but I can't start it to format it. It does a memory check and says 'press del to enter setup' but then goes black. The fan is still running, nothing beeps and no lights come on on the keyboard. I'm running xp and have tried F8, starting with the disc in to boot up from cd and even trying del to access the bios but it dies every time. Any suggestions?

Most probably due to a faulty disc...starting BIOS should not be a problem...Try using a third party bootable format utility if you want to format, but if your XP disc is faulty then you won't be able to reinstall using it..

"My PC's had it"
Does BIOS list your hd? Yes... then BIOS cannot actually access it because if it was doing so but failing, say, to find an OS it would mention it with an error message.
No?... then maybe fool about with the cables WITH POWER OFF, PLUG PULLED. Not so much concerned about your safety here, rather that of the pc.
Still doesn't work? Try the drive in a pc that boots.
Try starting the pc without your hd inside... what does BIOS report?
Unplug all hardware but memory.
Try starting it with a known good hd.