I haven't been able to control the bightness on my computer. It is running Ubuntu 16.04 LTS and dual boots with Windows 10. My processor is an Intel Core i5-6400T and my graphics card is an Intel HD Graphics 530 (Skylake GT2), if that helps. From what research I've done, the Skylake architecture is not very well supported on Ubuntu, at the moment. When on my Windows partition, I can control the screen fine, and my speakers which I have asked another question on. If there is anything I might be able to do, I will gladly try it. Thanks for any replies.
Edit1: I also use an HDMI to VGA adapter for a second monitor if that helps. Also my main monitor is an integrated computer (All-in-One).
Have a good one.