14 DAY TRIAL // A bug in Windows 10 April 2018 Update locks the display brightness to max settings, with users unable to adjust the configuration.
Posts on Microsoft Community forums show that the error hits several laptop models, including Toshiba and Lenovo devices.
“I upgraded my laptop over the weekend to Windows 10 1803. I noticed my display was set to max brightness. I am unable to use the F keys to lower the brightness. I am also unable to change the brightness in the display settings. My drivers are all updated. Any suggestions on how to fix this?” one user reported in the cited thread.
While a confirmation in this regard is not available, it’s believed the bug is caused by bad graphics driver, so reinstalling the software could help.
Rolling back graphics drivers could do the trick
On the other hand, there are several Windows 10 April 2018 Update whose devices were impacted by this problem and who said that rolling back to an older version of the graphics drivers fixed it. This indeed confirms that it’s all just a driver issue, though at the same time, it also signals a problem with the default drivers that are bundled into Windows 10 April 2018 Update.
It goes without saying that such a bug could lead to other problems on the affected laptops, including lower battery life and potential display issues. The screen is one of the biggest battery hogs, so keeping the brightness to the highest level obviously has an impact on battery life.
New driver updates should resolve the bug, though Microsoft itself could publish improvements in this regard with future Windows 10 cumulative update. The next rollout is projected to begin on June 12 when Patch Tuesday kicks off, but a confirmation on whether fixes for this problem would be included isn’t yet available.