My friends PC restarted randomly, after which his PC would get past the xp loading screen and BSOD with the error "unmountable boot volume". I had him put in an XP disk and run chkdsk. He restarted chkdsk partway through.

After which he could get into XP but he cant open any programs other than his antivirus (Avira), Word, IE and a java based game. All other programs gives him an error "The application has failed to start because the application configuration is incorrect."
Also his taskbar is greyed out and only the icons next to the clock and the clock show.

Any help would be greatly appreciated.

Hello and Welcome to PCHF

Can you get into the system and check the error messages by looking in the Event Viewer (Start->Settings->Control Panel->Administrative Tools->Event Viewer). This might help us find what the issue is.

Correct me if I am wrong, but I am gathering that chkdsk never finishes?

The first time he ran it, he restarted his PC thinking it was stuck. The second time it got all the way through.

I'll get him to do that now.

Ok he went start but he couldnt open settings because there is no button for it anymore.

He searched for event viewer and found it, but when he tried to run it it came with an error saying "mmc failed to initalize because it was installed incorrectly or a portion of the regestry is corrupted." It then said something about run this file to make sure it is registered. He did that and it came up with the same error for that program as well...

Solved - He formatted his HD and reinstalled windows which solved the problem.

Hello niggle we are happy it is resolved.

Formatting always does wonders to a system.

Thanks for visiting PCHF