COD4 Graphics Driver help

Whenever i click to run Call of Duty 4: Modeern Warfare multiplayer i get this message:

Error during initialization:
Video caord or driver doesn't support seperate alpha blend, glow will be disabled.

After that message the game closes...
Do i have to purchase a new VGA or is there a way i can get around this problem.
any help would be appreciated thanks.

you don't have direct x 9.0 do you....