yes
Go to PNY http://www3.pny.com/configurator/index.aspx?manufacturer=
or
Crucial http://www.crucial.com/?gclid=CNuj8NOEuqUCFQO87QodZm8EYA&cpe=pd_google_us&ef_id=S2Yzs9BkOIYAADSQTocAAADA:20101124180225:s
use their configurer to see what size and quantity of chips you need. Some need to be done in pairs. They could be add on or replace. And your os can affect what is useful. 32 bit windows can only use a max of 3.3 gig.