Brightness in Windows 10 keeps changing back to about 30%

[Meon1845]

The automatic brightness change is turned off and I have updated all my drivers, but the brightness of screen of my laptop keeps randomly changing to 30%, even when I'm working on it. My laptop is SONY VAIO SVS1311P9EB.

Can some of you help me, please?

 

[Lutfij]

According to this site have you updated your BIOS to the latest available? I can't hunt down the product support page for your unit as it may be out dated. edit: I tried to hunt it out on their site but can't find your corresponding model from their drop down lists (Sony Vaio Laptop>SVS>select model). Nevertheless have you installed the drivers in compatibility mode under a Windows 8 environment? The latest driver support shows it to be compatible with Windows 8.

Right click installer>Properties>Compatibility Tab>Windows 7/8 [from the drop down menu]

If the issue came about after a mandatory Windows update then perform a system restore to a point prior to seeing the issue.