compace computer? i have never heard of that manufacturer, did you mean compaq? are you sure that you spelled it correctly?
*EDIT*
it appears that in your double post, you labeled it "compact", so i can assume that this is a compaq computer we are talking about.
heres an explantation for your question...
compaq, like dell and emachines, are simply computer manufacturers. they do not make the internals of the computer, they just put them all together. the type of RAM that you wish to put in your computer relies solely on the motherboard, what the motherboard can support and how much the motherboard can support.