No offense, but you do have a crappy computer. The Celeron is made for business and extremely budget-oriented home PCs. You don't have a lot of ram. You don't have a good video card. In fact, your video card is one of the worst ever made. It's dwarfed by anything else that's made. It is, once again, strictly for business and low-budget home computing, not gaming.
Sorry, you won't get much in the way of any performance unless you part with some coin. You can try tweaking, but that will take a fair amount of time and work. It's not the hardware's fault, you're just asking a Geo Metro to be a drag racer. You get what you pay for.
umheint0's phat setup --> <A HREF="http://home.cc.umanitoba.ca/~umheint0/system.html" target="_new">http://home.cc.umanitoba.ca/~umheint0/system.html</A><--