* On your keyboard, ssthe Win + R key combo to launch Run
* Type “control panel” and press Enter.
* When the Control Panel window has opened, go to the drop-down list next to View by.
* Here, select Category.
* Next, click System and Security.
* In the next window, click Power Options.
* In the left pane, click ''Choose what the power buttons do''
* Next, click ''Change settings that are currently unavailable''
* Make sure to check the Sleep box down below.
* Click Save changes to bring the sleep option back.
* To confirm this, go to the Power menu and see if the sleep option has returned.