Have you ever noticed that the screen on your Surface will never stay at the brightness level you want? It’s probably because the adaptive brightness feature is enabled. Here’s how to disable it.
How to Stop Your Microsoft Surface RT from Dimming the Screen
Swipe in from the right-hand side of your Surface to brig up the Charms Bar, then tap the Search Charm to open it.
Here you will need to type “power” into the search bar, then choose to search Settings.
On the left hand side you should now see Power Options under the results, tap it.
Here, choose your current Power Plan and choose to change the plan settings.
Note: You will need to do this for all Power Plans you wish to eradicate this behavior from.
Then tap on the Change advanced Power Settings hyperlink.
Finally scroll down to the Display option and expand it. Now expand Enable adaptive brightness and switch the setting to Off.
That’s all there is to it.