
On Windows VISTA you need to click on the Start Button ( Orb), which is now just an icon. Same spot where the start button used to be in XP (bottom left). On the bottom line right next to the Padlock icon is an arrow. All your options for shutting down etc. are there.
The small reset button on your tower is only there if all else fails and you are completely frozen.
There is another couple of ways of shutting down the computer…
If you press the Large ON/OFF button, on your tower, just once quickly it will shut the system down normally. ie Windows will save your settings and shutdown. It is the same as using the shutdown command, only quicker.
If you hold in the ON/OFF Button in for about 4 seconds the system will shutdown immediately without saving. This is only good if you are in a a frozen state where nothing else can be done. Much like the reset button except the system will just turn off without restarting.
If you are going to access the computer from time to time with sometimes several hours in between, it is best to leave the system on and let the screen saver come on and the Power Save option should also be set to on (the Default is set to switch the Monitor off after 20 mins and the computer goes into sleep mode after 1 hour) You can find this by right clicking on the Desktop and selecting PERSONALIZE - SCREEN SAVER - POWER SETTINGS.
Personally I prefer to switch the computer off only when I go out or when going to bed at night, otherwise I leave it running through the day and let the screen saver and power save modes take over.