Hi,
One common solution from different manufacturers is to uninstall/reinstall the graphics card driver.
- Go to Device Manager and uninstall your graphics card driver.
- Check in Programs and Features for anything related to your graphics and uninstall it as well.
- Download and install the latest driver from the manufacturer site.
NVIDIA: nvidia.com/download/index.aspx
AMD:
http://support.amd.com/en-us/download
Intel: https://downloadcenter.intel.com/
- Once installed you can do screen brightness adjustment from the graphics control software.
- Most of the time it would be located in Advanced tab.