restarting again n again

Impossible to say without some more details so restart the computer and as it powers up, tap the Function 8 key several times to bring up the Advanced Boot menu. Select "Disable automatic restart on system failure" and when the startup stalls at a blue screen, take note of the numeric code 0.0000?? and ANY_WORDS_JOINED_UP by underscores. Post those details back here and someone will be able to help you. It would also help if we knew which operating system you're running - XP, Windows 7, 8?