My new laptop is Acer Aspire 4740 which configuration is very good. But I am having problem in adjusting the brightness after installing Ubuntu 10.10. This problem is occurred due to Intel HD graphics with the BIOS firmware version 1.05 . Whatever, I had to do a little hack to fix it.

So, first I updated the Bios firmware from  version 1.05 t0 version 1.09. You can download it from http://www.acer.co.in/ac/en/IN/content/drivers. I downloaded the .exe file and install in windows.

Then reboot to Ubuntu. And edit /etc/default/grub file. Type this in terminal

sudo gedit /etc/default/grub

Then change this line: GRUB_CMDLINE_LINUX_DEFAULT=””

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

And also chnage this line: GRUB_CMDLINE_LINUX=””

GRUB_CMDLINE_LINUX="acpi_osi="

Then update the grub

sudo update-grub

Done. Still the brightness is not automatically adjusted when power cord has been unplugged, but i can adjust brightness by arrows keys. I didn’t get any better solution than this. Happy Hack 🙂