Looks like X was not fully installed. What exactly did not get installed? Does it work for you, or are you working from the cli? in the event that it is installed, or even working, then
$ /sbin/lspci (assuming that is where lspci is located, use 'locate' to find it)
my output looks like this:
01:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G400 AGP (rev 82)
Then, in the /etc/X11/XF86Config, make sure you have a section like this-
Option "agpmode" "2"
Option "EnablePageFlip" "True"
most important are the BusID, and Driver.