[Ubuntu-BD] how to install intel G31 graphics driver

[nazmul mahmud]

hello brothers,
as salamu alaikum. this is my first mail here. i attended the last ubuntu workshop organised in Presidency University.

i'm using ubuntu for the last 3-4 months. my ubuntu version is 9.04.
i had a nvidia graphics card in my old cpu, used compiz successfully then.
but recently i hv totally changed my cpu. now i hv Gigabyte G31 (GA-G31M-ES2C) motherboard where there is built in intel graphics card (Intel Graphics Media Accelerator 3100).
though i hv changed my cpu, but i'm using my old hard disk where my ubuntu is installed.
my built in graphics card is not detected now, my ubuntu is running in low graphics mode.
in the system>>administration>>hardware drivers, there is no suggestion for my graphics card.
now hw can i find and install my graphics card?
i can't use compiz now and that's why i'm nt enjoying using ubuntu at all.

i have read the recently published bangla ubuntu tutorial, tried the way stated there.
here is what is shown in the terminal window-

nazmul at nazmul-desktop:~$ sudo apt-get install xserver-xorg-video-intel
[sudo] password for nazmul: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
xserver-xorg-video-intel is already the newest version.
The following packages were automatically installed and are no longer required:
  fakeroot dkms patch
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 27 not upgraded.
nazmul at nazmul-desktop:~$ 

still my display is not ok.
plz help me, dear brothers..