Windows 8.1 cant change brightness

[JuztBe]

Hello. For some reason I can't change brightness settings anymore. If I use control panel "More power option" and change things there nothing changes. Even Fn+arrow keys doesn't allow to change it(Acer ).
Maybe there are some sort of automatic brightness setting witch forces stuffs like that?

[RegularRlofe]

What laptop are you using and what are the specs?

[JuztBe]

What laptop are you using and what are the specs?

Acer V3-772G .  i5 4200M 750M 8GB of ram. It worked just fine couple days ago.

[RegularRlofe]

1) Download the latest driver here: http://www.geforce.com/drivers and perform a clean install.
 

2) After, check if "Enable adaptive brightness" option is enabled and if yes try turning it off to see if that will help. This option is located under the Windows 8 power options. You can access it via the Windows control panel > Power Options > Change plan settings (which ever plan is active) > Change advanced power settings > Display > Enable Adaptive Brightness.

3) Check if you are able to change your brightness.

 

Hope this helps  

[JuztBe]

1) Download the latest driver here: http://www.geforce.com/drivers and perform a clean install.

 

2) After, check if "Enable adaptive brightness" option is enabled and if yes try turning it off to see if that will help. This option is located under the Windows 8 power options. You can access it via the Windows control panel > Power Options > Change plan settings (which ever plan is active) > Change advanced power settings > Display > Enable Adaptive Brightness.

3) Check if you are able to change your brightness.

 

Hope this helps  

Adaptive brightness is disabled. Will try to reinstall drivers. It seems it gets darked when i open darker webs, pictures, games, and brighter when i open bright pictures, webs.

[RegularRlofe]

Adaptive brightness is disabled. Will try to reinstall drivers. It seems it gets darked when i open darker webs, pictures, games, and brighter when i open bright pictures, webs.

If the problem is not fixed, make sure that the laptop is plugged in properly and is on high performance power plan.

[JuztBe]

If the problem is not fixed, make sure that the laptop is plugged in properly and is on high performance power plan.

Reinstalling GPU drivers worked, thanks.

[EmeraldFlame]

You may want to look around on forums that are more specific to your model to see if a registry change is needed. While I am not very familiar with nVidia's mobile graphics solutions, many of AMD's cards needed a registry tweak to work with Windows 8's brightness controls. From what I have been able to tell, a lot of cards and drivers before Windows 8 launch were set up to control the brightness directly through the graphics driver. With windows 8 however, native brightness controls were enabled, but a lot of cards were still trying to change through the driver and Windows 8 just wouldn't accept that.

For example, I have a Asus G73JH and when their drivers started to support Windows 8, I had to change HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0001\KMD_EnableBrightnessInterface2 to 0, essentially turning the driver brightness control off so it would instead interface with Windows 8 native. Like I said that registry key is specific to AMD cards, but I wouldn't be surprised if there is a similar issue with nVidia cards too.