I went to the Packard Bell site and typed in the serial number etc and followed the instructions. The procedure generated a CD and I rebooted with this and the BIOS updated (apparently successfully). I was reading a message saying "Press any key to continue...." when the screen went blank. I didn't get a chance to press a key! Since then, on power up, the disk light comes on and the CD drive as well but nothing else. Is it possible to reset by removing the CMOS battery? If so, where have they hidden it!?