Ok lemme guess... You either have one of three machines... An HP, a Compaq, or an E-Machine all three of which nine times out of ten have onboard video. Yes your computer physically does have a single stick of 256mb RAM but 32Mb of that is being consumed by your onboard video. Unfortunately even if you do upgrade your RAM may find you need some help in the video department. Your best best would be to get a decent video card upgrade providing your machine has an AGP or PCI-X slot and another 256mb RAM this will relieve your comp from rendering the massive world of WoW from the onboard video and will give you a boost to not only play WoW but also other games.
GeForce FX 6200 are dirt cheap these days and so is RAM. Best bet is
http://www.newegg.com
Hope this helped,
-Allshow97