Working in network support environment, I get this question asked so many times, I've stopped counting long time ago :)

Here are 3 ways of doing it:

1. CTRL+ALT+END to get the shutdown/reboot menu.

2. Or press START button, then click the "Windows Security" button, which is right above the log off/disconnect buttons. Then select "Shutdown" from the menu and reboot, or shutdown.

3. Or enter command prompt (start/run/cmd), type in: SHUTDOWN -r -t 01 (for reboot) or SHUTDOWN -s -t 01 (for shutdown).