Xp pro keeps rebooting

Hello,
hi,im using xp home edition on my computer, it keeps restarting and if i choose to start in safe mode, start windows normally or last known good configuration, it still restarts, ive tried pressing f8 and still get the same, can anyone please help me fix it? or have any idea whats causing the problem? any help would be really appreciated thanks,

after holding down f8 and going to the blue screen i get the error message

STOP 0x000000 (0x89BFA900,0xC0000006,0x00000000,0x00000000)

Len in Birmingham