Hi,
· Did you make any changes to the computer prior to the issue?
Let’s disable automatic restart on system failure and get the exact error message. Follow these steps to disable automatic restart.
a) Restart the computer and, press and hold the F8 key as your computer restarts. You need to press F8 before the Windows logo appears.
b) On the Advanced Boot Options screen, use the arrow keys to highlight the Disable automatic restart on system failure.
c) Log on to your computer with a user account that has administrator rights and check if you’re able to login.
I would also suggest you to check for any error logs in the event viewer related to the crash or blue screen error. Refer to the link provided below to check the event viewer.
http://windows.microsoft.com/en-US/windows7/What-information-appears-in-event-logs-Event-Viewer
Method 1: Try to boot into safe mode and check if the issue persists. Refer the following link to boot the computer in safe mode
http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode
If the issue does not occur in safe mode then, start the computer in clean boot to check if any third party program is causing the issue. To configure your computer to clean boot refer the following link.
http://support.microsoft.com/kb/929135
Note: After you have finished troubleshooting, follow step 7 in the article to boot to normal startup.
Method 2: If you’re able to boot to the computer in clean boot then, follow the steps provided in the following link and check if that helps.
‘Resolving stop (blue screen) errors in Windows 7’
http://windows.microsoft.com/en-US/windows7/Resolving-stop-blue-screen-errors-in-Windows-7
Method 3: If you’re unable to boot the computer then,****I would suggest you to perform startup repair using the Windows 7 disc and check if that helps. Refer the following link to perform startup repair.
‘What are the system recovery options in Windows 7?’
http://windows.microsoft.com/en-US/windows7/What-are-the-system-recovery-options-in-Windows-7