Ubuntu 10.04 Cant Adjust brightness on my lenovo Thinkpad?

oh，I've met this problem before.All you need to do is:

sudo gedit /etc/X11/xorg.conf

find segment like this:

Section "Device"
Identifier    "Default Device"
Driver    "nvidia"
Option    "NoLogo"    "True"
EndSection 

change it like this

Section "Device"
Identifier    "Default Device"
Driver    "nvidia"
Option    "NoLogo"    "True"
Option "RegistryDwords" "EnableBrightnessControl=1"
EndSection 

JUST ADD THIS LINE: Option "RegistryDwords" "EnableBrightnessControl=1" !

Then restart,It will work.

I was able to get my brightness keys working on my Lenovo W530 on Ubuntu 12.04 (posting here to help people looking for answer in future)...

These days X automatically configures itself, so you can't just edit the xorg.conf file, you, instead need to add a section to a file in /usr/share/X11/xorg.conf.d/ and X will include that section in the configuration that it automatically generates.

So to get the screen brightness keys working with your Nvidia graphics card, create a file in the xorg.conf.d directory, e.g:

sudo gedit /usr/share/X11/xorg.conf.d/10-nvidia-brightness.conf

Paste the following into the file:

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "Quadro K1000M"
    Option         "RegistryDwords" "EnableBrightnessControl=1"
EndSection

Log out and log back in, or reboot, and your brightness keys should now work!

(I blogged this here)