Please I am new to ubuntu 14.04 and i can't adjust my screen brightness. I'm using HP Pro book-450-G2. but i dual boot the ubuntu with windows 10 and my brightness can be adjusted in windows 10.

1 Answer 1


You can install xbacklight with sudo apt-get install xbacklight, and then try xbacklight -set 10.

If that does not work, then open up the folder /sys/class/backlight/ and see if there are any entries. If not, then you probably don't have your video drivers installed.

Edit: OK, the following seems to have worked for OP: Brightness setting not working on Xubuntu 15.04 ( vivid vervet)

  • Please, i tried it and it didn't work, but there are entries in /sys/class/backlight. the entries are acpi and intel. Feb 13, 2016 at 16:58
  • @RichmondSelikemChris-Koka: Could you please see if <pre>tee /sys/class/backlight/intel/brightness <<< 5</pre> or <pre>tee /sys/class/backlight/acpi/brightness <<< 5</pre> works?
    – mkdrive2
    Feb 13, 2016 at 17:20
  • Please I tried the Brightness setting not working on Xubuntu 15.04 and it is now WORKING!!!!!!!!!. yaay. I'm so happy. thank you and God bless you. Feb 13, 2016 at 17:21
  • Please i need one more thing. Feb 13, 2016 at 17:22
  • I can't connect to wifi networks. I can only use an ethernet cable for internet connections. there's no option for me to even see available wifi Feb 13, 2016 at 17:23

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