I recently updated my pc to windows 8.1, and a short while after the update whenever I tried to sign into the admin user all that happened was a pop up (which I uninstalled from one of the other accounts) I am able to open the task manager and such with ctrl+alt+delete but no desktop appears nor can I access the start menu. The strange thing is I can access one of the other users on the computer (I didn't check the third because I dont have the password). Any solution ideas