I've been asked to try and fix a friend's pc. When it is started the hdd spins up and the post appears to progress ok. As it begins to load Windows the improper last startup screen appears. When I try to start it from there it goes to a blue screen almost immediately. It tells me there is a Windows stop error due to an unmountable boot volume. I'm not familiar with this problem, can anyone help, the pc is running Windows xp.