Try to start it in safe mode. When you turn on look at the screen and there should be some text. I think you press delete but someone else will tell you if thats wrong. If you can then you will be able to gain acess to files that have been courrpted. It might be that some files are missing so you might need to reload the setup disc that came with pc to correct it. or you could have a virus Proberbly loose information on pc or it may even need reformatting hth