Mobo is Epox AF590 SLI2. Keyboard is PS2. Keyboard and machine work perfectly when in WinXP SP3. Delete key will get me into the BIOS but then no keys work *inside* the BIOS menu. Need to hard reboot the machine to proceed. Thank you.

I guess you could try another keyboard. Might be a power issue with a non-standard keyboard. Did it ever work correctly? Playing to the angels Les Paul (1915-2009)

I built the system and have been inside the BIOS previously BUT now that you ask I think I may have built it (and therefore been inside the BIOS) with a different keyboard. Will try the other KB to see if that does the trick. As for the KB that currently isn't working inside the BIOS, it's an old but standard keyboard from Compaq (model #KB-9965). I should also add that I did try another KB but it was a USB version and I don't think that will get me anywhere. OK, tried the other PS2 keyboard and no difference. I still can only get into the BIOS (using Delete key) but once inside the BIOS the KB is dead.