Here is a tip on how to shutdown windows without actually shutting down the computer.
When you click on the SHUTDOWN button, make sure to simultaneous press SHIFT Button. If you hold the Shift key down while clicking on SHUTDOWN button, you computer would restart without restarting the Computer. This is equivalent to term "HOT REBOOT".
make sure you are using fast switching for user. For those who don't know here is the method :
goto control panel>> doubleclick user account>> use accounts window opens>>> click on change the way user log and log off, there you will make the changes by marking the two boxes.