1. Click Start, All Programs, and then right click on "Command Prompt".
2. From the context menu click on "Run as administrator".
3. If User Account Control prompts you to allow the action, click on Continue.
4. In the command prompt window, type "powercfg –h off" (or "on" without the quotes) followed by Enter button.
4. Close the Command Prompt window and you're done :)
