After POST, immediately and repeatedly press the F8 key. You can stop pressing the key when you hear beeps everytime you press the F8 key, or when you see the avanced boot menu.
Once you get to the advanced boot menu, you should see several options. You want to highlight "Restart On Boot Failure" or something like that. Press enter when it is highlighted and it should stop the restart cycle.
However, after doing so the computer will restart, but just once. If the boot fails again, the computer will stop on the BSOD. Read through the message on the screen. Generally, the BSOD tells you what is causing the failure.