What can I do about the blue screen of death on my computer when I boot up?

Hopefully you still have your original windows xp setup disk. make sure you enter bios and the computer is set to boot from disk. insert your dvd setup disk and reboot your pc. With any luck, you will be given the option to repair your windows. Just follow the prompts. If you want to retain files on your pc, don't do a reinstall of xp.