Restarting

Start > Turn Off Computer > Restart

Will restart the computer.

Shutting Down

Start > Turn Off Computer > Turn Off.

Will shutdown the computer (turn it off).

Logging Off

Start > Logoff > Logoff

Logs you off of the desktop, closing all open applications, and takes you back to the Welcome Screen.

Switching Users

Start > Logoff > Switch Users

Keeps you logged on and takes you back to the Welcome Screen, allowing you to log on to another user account. (The welcome screen will show you if you are already logged on.)