Hi guys, have a weird question. I currently own two HP Elitebook 840 G2's. I bought them from someone recently and both came with Windows 8 Pro. The seller reformatted them to factory conditions for me. I upgraded one to Windows 10 Pro, and I left the other one with Windows 8. Everything on them work, but I can not get the brightness hot keys to work on either one of them. At first I couldn't even adjust the brightness on the one with Windows 10 Pro through the control panel, but then I downloaded a video driver to get that back for me so I can adjust it through the control panel at least. I can adjust the one with Windows 8 Pro through the control panel as well. I just can't get the hot keys to work. Apparently, this is a very common issue on HP laptops that have been upgraded to Windows 10, but I'm still having the issue with the one that has Windows 8 Pro on it. Can anyone help me figure out how to fix it? I've done a lot of googling on this and there isn't a clear solution.