Ping and Graphic issue w/ Battlefield 2 online multi gaming.

Hello I'm running on

BFG Tech BFGR78256GSOC GeForce 7800GS 256MB 256-bit GDDR3 AGP 4X/8X Video Card

2.4GHZ Intel

1024 ram

about 21 GB free on my HD

and Cox (supposedly) fast internet with 7MB down connection an 1MB upstream connection

I have almost all the settings on low maybe two options on medium.
My general ping levels are around 100 to maybe 40 but if I up the graphics it starts to lag. Sometimes even at a 24 or 16 it will still glitch I've notice that happens on the big 64 maps. Can someone give me some advise as get the most out of what I have. Or what I can do to improve my current "good but not exactly what I was expecting" performance. A friend of mine told there shouldn't be any issues with the graphic levels on high. But the game proves different.

The processor, i'm going to assume is a pentium 4... I have a similar system with a 7800gs oc, 2 gigs pc3200 and a pentium 4 3.2ghz, runs good on medium settings (i can play high on only 16 sized maps, and its not an option when theres no chopper!) suggest you get some ram, 2 gigs is nice, and the processor might need to be looked at.