To shutdown your PC, you go on Start – Turn Off Computer – Turn Off, but you can do this by just pressing the power button of the CPU. To do this, you will have to customize your windows a little and then you can switch-off your PC on single hit.
Go to the “Power Options” on your PC from the Control Panel and then click on the “Advanced Tab” of the Power Option window. There is a “Power Button” option over there which will let you select from couple of options to do with the Power Button on CPU. Choose “Shut down” from the list. Which means when you will hit the button button on running PC, it will start turning off.
When you will enable “Hibernate” option from he Hibernate tab on the same window, the list will also include “Hibernate” as an option as well. This way you can choose from shut down, stand by or hibernate for the power button of CPU.