Brightness goes down automatically when I start a game?

Every time I start a game my screen automatically gets darker.

Was in the games Overwatch and Minecraft so far the case.

I have a Game Booster installed on my PC but it is not up to him to uninstall it and the problem still exists.

Does anyone know how I can fix this?

I'm grateful for every helpful answer.

It may be due to the booster because so much effort is trying to get or it is on the screen

In the settings of Windows you can disable the automatic brightness for laptops

That is already deactivated

Can be but see no adjustment in the booster which changes the brightness

Uninstall the booster and check if you still have the problem

I have made the problems are still there

It may be that your PC / monitor switches to a cinema / gaming mode and changes the colors / brightness / resolution accordingly. Would browse the menu and see if you can find such.

Did not find anything in the settings