Automatically Shuts Down After Boot

This type of behaviour usually occurs due to a minor error in that profile/configuration. Often loading something that is corrupt. Eventually you will neeed to find out what is faulty and fix it, but to get you logged on properly with that user:

Log on to the system as another user with Administrator access or in Safe Mode.

Go to My Computer >> Control Panel >> System >> Advanced tab >> bottom third is Start Up and Recovery activate the Settings button in this section. About the middle ofthe sub-window is a box beside 'Automatically Restart', decheck this box, click on 'OK' click on 'Apply' and close the windows. Reboot the system.

In future minor errors will not cause a reboot and the system will continue to load. If you have logging enabled a check of the logs will show what needs fixing.

Not sure if your problem has been fixed for you or not yet, but there is also another possibility. You can also try this:

1. Boot into safe mode
2. Start > Run > gpedit.msc
3. Go to: Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options
4. Near the top there is a line that reads "Audit: Shut down system immediately if unable to log security audits" - If that is enabled, you might try disabling it to see if it clears up the problem.
5. Ifit does clear up the problem, you will have to do a little troubleshooting to figure out why it is having problems logging security audits because you definitely want to have auditing working.