Blue screan

Hello,
i turn on my son computer. a black screan comes up and startes counting down for windows xp to start. the windo ex trys to start up. Then a blue screen pops up with saying windows has shut down. and all so says unimoutable_Boot_volume. And it tells you to go into safe mode and stuff. well i tryed that and it keep going to the blue screen. there numbers at the bottom of the screan to.. i also have tryed to reboot it to and the same thing with the blue screan coming up with the same saying.

Technical Information.
0x000000ed
(0x84A695900, 0xc0000006, 0x00000000, 0x00000000).

Can some one please help. i also want to put windows 7 on it.