If you rely on Power options in Windows to enter your system into power-saving mode after specified time to save energy and you can also use on/off button on Monitor to save more energy, but Sleeper is a freeware portable tool that lets you send your monitor to power-save mode with a keyboard shortcut.

Want to Disable Sleep button on Keyboard? Here is how to do it

Using Sleeper

Download and extract Sleeper archive contents to a folder. Create a shortcut to the Sleeper executable on desktop, assign a keyboard shortcut to it whichever you feel comfortable and not interferes with other applications by right-clicking on shortcut icon > select Properties > from the Shortcut tab.

Sleeper  doesn’t have any user interface, it sends “sleep” command to Windows and closes itself automatically, assign a shortcut to the program and use it to put your monitor into power-saver mode. Press any key on  the keyboard or move your mouse to exit power-save mode.

Sleeper works on Windows XP/Vista/7.

Download Sleeper