i think you mean your motherboard can support 2 gigs.
you prolly have 3 to 4 actual slots.
im pretty sure you have to buy a tray kinda thing that plugs into one of the slots that creates a bunch more slots to have a ton of sticks in.
never seen a motherboard with more then 4 actual slots on it. (then again i never went out looking.)
BTW, mine can go up to 3 gigs. But we not in competition.

(sorry, hehe)
-EDIT- Actually i just thought about that.... 4 slots, with a 512 stick in each is 2 gigs. so yea, guess you can get in 2 gigs without expasion slots. sorry, hehe.
mine can goto 3 gigs, but only has 3 slots, so eh *shrugs*