Windows 10 Computer brightness get dims after computer startup

Every time I reboot, the computer starts in the normal way and once most of the start-up programs have booted, the screen then dims to a point where it is difficult to see. Why?

This PC is upgraded from Windows 7 to Windows 10 1509 few years ago and keep upgrading to the latest version and now I am in Windows 10 version 1909.

I followed some troubleshooting steps my self like go to settings on the start menu and go to the Display tab, I can adjust the brightness level on the slider. The trouble is when doing this, the “Apply” button does not become active and it stays greyed out so I cannot click on it to keep it at the level I want.

The same problem happens if I reboot the computer again, the screen goes dim, and the slider in system settings is back at its lowest setting once more and I have to adjust the brightness level again. I did change some power plans and tried to change some of them but still, I cannot stop the display dimming on boot up.

What could be the issue? is my OS causing the issue or related to PC hardware?

Thank you


Hi friend i think ur problem it’s just with the os try this :èmes-de-luminosité-de-lécran-après-la-mise-à-niveau-de

Hi @Palmer,

I think the Adaptive B rightness option might have been enabled in your PC. Adaptive Brightness is a feature that adjusts your screen brightness according to the light surrounding the PC. To disable this, kindly follow the steps below.

  1. Open Settings ,and then select System .
  2. Select Power & sleep , and then click Additional power settings on the right corner of the window.
  3. Click Change plan settings located on the right side of the power plan that you are using.
  4. Go to Change advanced power settings , and then select Display .
  5. Click Enable adaptive brightness , and then toggle it Off .
  6. Click OK to save the settings made.

Please let me know if the above process solved your issues.



I had this issue to solve it, I had to change the registry setting. Now, finally the screen brightness is back.

Registry path:

HKEY LOCAL MACHINE\SYSTEM\ControlSet001\Control\Class{4d36e968-e325-11ce-bfc1-08002be10318}\0000 (or 0001)

Double-click the item of FeatureTestControl , set the hexadecimal value to " fb20 ", and click OK.

Now restart your PC! Screen brightness is back, no more dim screen.

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