If your PC literally just shuts itself down, it's more of a hardware-based problem. Try using the character that you're able to play with, go to the same spot as your main character and see if it shuts your computer down still.

If the computer shuts down still, it means your power supply/source does not have sufficient resource to generate that certain area. It should at least give you a BSOD error, a quick restart, but not a sudden shut down. It also can be an overheating issue.

Try going into Control Panel>Administrative Tools>Event Viewer>Right-click System and search got Critical. See if you find anything.