I have an HP Pavilion dv7.After an auto update in Windows 10 I am unable to change the brightness.
If you think that it has been happening after installing an update then try to uninstall the update and recheck the issue.
You may go for a System Restore. Select any restore point prior to this update.
Uninstall, reinstall and update Graphic Card driver. Visit the website of the Graphic Card manufacturer to download the latest driver.
After this download and reinstall Quick Launch Buttons from HP’s support site.