Log on to the Windows 8/Windows 8.1 computer with the user account on which you want to adjust the screen brightness.
From the Start screen, click the Desktop tile.
On the desktop screen, hover mouse to the bottom-right corner of the window.
From the displayed Charms bar, click Settings.
On the Settings pane that appears in the right, click Control Panel.
Once you are on the Control Panel window, go to System and Security.
Click the Power Options category.
On the Power Options window, click the Change plan settings option representing the Balanced (recommended) radio button.Note:Balanced (recommended) power plan is selected in this demonstration. In case any other power plan is selected in your Windows 8/Windows 8.1 computer, you must click the Change plan settings representing that power plan.
On the next window that appears, move the horizontal sliders from left to right or right to left in order to increase or decrease the screen brightness respectively.
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