Improving performance on a Intel 82845G

While it probably can't be done, I want to know if there is any way I can improve the performance of this crappy, crappy card. Even on high quality it seems I can never achive the detail that is shown in so many screenshots.

More specifically, I want post process effects. They won't enable. Whenever I check the box to enable them, it disables whenever I hit okay. Just incase it might be needed, my system specs:

Intel Celron D 2.66GHz
764mb Ram
Video Card, read above

Is that an on-board card?

Sadly, yes.

Well theres nothing you can do, its clearly the bottleneck

Read the thread i made
and may i suggest a radeon 9550-9800xt

I have no AGP/PCI-E slots, so my range is VERY limited. Not to mention I am short on cash.

I am currently looking at an Indo3D GeForce FX 5600 128mb, it's about the best I can get that will work with my system AND be in my price range.

Radeon 9250 is pci, 256 megs, very affordable

While I must admit, it is a VERY nice card, one that if I owned it, I would never take my eyes of GW. However, $200 is out of my price range.

that card isnt 200 bucks, my friend has it for 70 ...