BSODs can happen for almost an uncountable amount of reasons, but is indeed easier to troubleshoot if you have the exact BSOD error.
You can stop autorebooting by rightclicking your "My Computer" and Properties. go to the Advanced tab, and Startup and Recovery, Settings button. and obviously untick "Automatically restart".
now try to BSOD the computer again, and give us more info. including what CPU/Board, etc, and if its BSODing in any other cases.