|Have a check here if not already done:|
Open Power Options by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Security, and then clicking Power Options.
On the Select a power plan page, on the left, click Choose when to turn off the display.
Doing this adjusts settings only for the plan that you're currently using. To change settings for another plan, click Change plan settings next to the plan that you want to change.
On the Change settings for the plan page, choose the display settings that you want to use for this power plan when your laptop is running on battery and when it's plugged in.
Click Save changes.