my brother is having problems with his pc, he is using windows xp professional. well he was until he put in a new hard drive(120ghz). he was using this for approx 8 hours after installing h/d then it started to freeze and shut down, when restarting it comes up with <systemroot>windows\system32\hal.dll. files missing, needed to start windows. now he cannot get on the start up screen he has taken out the new h/d he installed to see if that made any difference but it hasnt , he has asked me as he obviously cant get help and you ppl are gr8 this is the first place i came. hope you can help
sulky

Try looking at some of these links. The first one will hopefully sort things out.

http://www.google.com/search?q=hal.dll%20missing

When you say he put in a new hard drive: Was it in addition to the old?

Or did he replace the old with the new & reinstall XP?