From what I heard of, here is what happened Windows Explorer is not working. To fix this, first press the famous ctrl+alt+del key sequence and select "Start Task Manager" go to file, select the create new task option, type "explorer.exe". If at the last step you get an error message, type instead "cmd.exe" and from there type "explorer.exe". If the command prompt is not visible, switch to it anyway and type the command anyway also. Windows Explorer should restart and everything should be back to normal.
If you have already done this, try searching for explorer crashes for the only other solution I can think of is to back up all your data and reinstall Windows.
Sorry for the long explanation.