preferred terminal emulator is.). Run lspci. This should display all
the PCI/AGP devices in your system. This should help you to discover
what your video card is.

For example, the server I happen to be logged into displays
0000:00:0e.0 VGA compatible controller: ATI Technologies Inc Rage XL (rev 27)
as the 5th line of output from lspci.

If you're not comfortable editing the config file your self you can
run the following command on a Ubuntu or Debian system:
dpkg-reconfigure xserver-xorg
to reconfigure your xserver (I'm sure Ubuntu has a pretty GUI tool
that runs in X, but I never use it!)

After changing the config file you will have to restart your XServer.

-- 
Andrew S. Zbikowski | http://andy.zibnet.us
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