when pc is turned on after bios screen it goes black and leaves this message; invalid boot.ini file, booting from c/windows, <windows root>/system32/hal.dll missing or corrupt. She says that she was hacked into by someone. Does anyone know how to fix this problem? I'm very new at all this.
thanks

Boot off the XP CD and do a repair install over the existing Windows installation to fix these files.

One how to use repair installation: http://www.michaelstevenstech.com/XPrepairinstall.htm

When you get it back up and working, visit windows update and download the updates, install antivirus and a firewall and also scan your pc regularly with Spybot and/or Ad-aware.

I'd recommend Trend Micro's Internet Security suite. It has a good firewall (similar to Zone Alarm), Spam filter, plus parental control, spyware detection and of course antivirus. I also found it not to slow down the machine to a crawl and also it updates automatically without a hitch (these 2 problems I had with Norton).

Trend Micro should shout if it sees anykind of trojan activity, hence (hopefully) not repeating what has already happened.

Good luck