Is it the machine, or just the Control Panel, that is "shutting down"?
Have a look at this similar type thread, see if you can use any of the ideas and suggestions?
Weird error when opening User Accounts from Control Panel
thread779-1220928
To get further information about any error look in your Event viewer.
Look in the System or Application folder. You can get to the Event Viewer via right click My Computer icon and select Manage.
Any errors logged in the Event Viewer can be expanded by double clicking on the error line.
Take any event error I.D. number and search for it on these sites.
Also check any "Information" line that mentions "savedump" and you should find reference to "recovered from a bug check". This is the Stop Error that caused your problem.
You can also turn off "automatically restart after an error" so it will just halt at the fault and display the full Stop Error and blue screen.
Right-click My Computer, and then click Properties .
On the Advanced tab, click Settings under Startup and Recovery .
Click to clear the Automatically restart check box under System failure , and then click OK . The error message on a blue screen should remain on the screen so you can record the error information.