Fuction keys for brightness not working in Ubuntu 14.04 and 16.04

Try adding the acpi_osi=\"!Windows 2012\" to the grub command line. You can do that by adding acpi_osi=\"!Windows 2012\" to the variable "GRUB_CMDLINE_LINUX_DEFAULT" in /etc/default/grub GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=\"!Windows 2012\" Then run "sudo update-grub" Restart computer Enjoy!