Presario 2274 display adapter problem

The HDD was formatted by the previous owner and W'98 has been loaded.
It's running with an 15" SVGA monitor, set up correctly but will only display @ 640x480 with max 16 colours. I assume there's a driver problem - any ideas?
Have tried to update the diver off the W'98 CD and via Microsoft on-line update but both ways the result is that the best driver is already installed????
kenward@kenward.screaming.net
Good on ya