Virtual Memory low???!!

My computer is VERY VERY slow AGAIN! This time it tells me that "they" are trying to increase my virtual memory as it's very low.. which I do not understand what it is all about!!? Just know that it takes forever for everything to work :( Sick lor.. Good thing I'm such a patient person. But I don't think I have much time left liao leh - i.e. time to wait forever.. Sigh! Need to quick quick do things liao..