I've run into a serous problem on my sons' PC that needs immediate attention as his school work is on there and he has an important exam next week.

He has a Dell desktop computer, not sure of the model at present...it doesn't have a reboot button and after it froze on me I used the on/off switch on the power bar it's plugged into to shut it down. Now after that when we turn it on we get a black screen suggesting 3 different safe modes to go into but when we try them we get a blue screen...so we have no access to his documents. My son had this same problem once before and a friend managed to get it working again without having to re-program it and he didn't lose any files. The friend who helped before is up to his neck with work and other stuff so are there any techies around here with some basic tricks up their sleeve or suggestions what I should try...in simple to understand terms that a not-so-computer-saavy person might try? If I can't recover his documents I am going to feel sooo bad as this exam counts for 50% of his mark in that subject and he did so well the rest of the year with other related work.

Many thanks for your attention.