Loaded XP onto a new empty 40GB HDD. No problems with installation and all running well. Person I was doing it for picked up the system then rang to say it would not boot into Windows XP saying that system32/ntoskrnl.exe file was missing. They tried several times but it would not load. Retrieved system and set it back up at my workshop. Booted into windows with no problem. Did ten consecutive boots with no problems. Returned PC to friend and at their place same thing happened again .. won't boot into windows. Granted there is a different new monitor and mouse/keyboard at their place but otherwise all is ther same...Any ideas??