Hi,
Have you tried to boot into safe mode?
If you can boot into safe mode, go to device manager, click the Advanced tab.
In the Startup and Recovery area, click the settings radio button.
In the System failure area, unckeck the box "automatically restart", click OK.
Exit device manager and reboot. You will receive a BSOD instead of re-start.
Post back to NG the exact warning messages for investigation.
Peter