BLUE SCREEN ON XP STARTUP?

The Blue screen you mentioned, known as Blue Screen of Death (or simply BSOD) is a critical system error indicating that you have a malfunctioning hardware or a corruption of data in RAM. Which means that either one of your hardware failed or your RAM is damaged (or loose). Secure all the connections like Molexes, IDEs, SATAs, Jumpers .... also remove your video card (If you have any), rub the copper connects with an eraser (the one you used to erase pencil marks) and insert them again, do the same for your RAM modules. Also check that the SATA or IDE cables are not damaged. In 80% of BSODs I encountered in various computers, the case is .. damaged/malfunctioning/loose RAM.