I would highly suggest more RAM also, as it is the cheapest way to upgrade your computer.
try for 4gb, but first I need to know more about it.
I would like you to get a tool called "CPU-Z" which displays information about your processor/mobo/RAM.
CPUID - System & hardware benchmark, monitoring, reporting
Once you open it give me a screenshot of the "Memory"
Also something else to think about, I'm going to assume you have two sticks of RAM where each is 1gb.
But if that isn't the case and you only have one stick of 2gb, you could upgrade much cheaper.... If you have time you should open your case and look, or look at the SPD tab of CPU-Z and check the slots and see if it says 1 slot or 2 slots.