bf2 is cpu heavy l have a 2600+ a 3200+ and an fx55 bf2 runs good on all l need to put the x800 pro in the 2600+ as it has no vid card , the 2600+ amd isnt 64 bit not that it matters when bf2 is 32 bit code, make sure any viris scanning crap is off, msn and the like off, give your cpu as much power as possible, lve found my system chewing 1.2 gigs of ram running bf2 and fraps and media player [fx55 ] , maybe try upping your page file to 512 or more, the chop can be alot of things , ram getting re addressed , not enough ram can cause this , your pc dont spec wise look bad, check your backround applications, and before you enter the game set your desktop 3D settings to performance or lowest , then, set everything in the game to min, then aplly settings 1 at a time and the first should be view distance, leave textures low till last, texture can use heaps of memory, try that its a pain 1 setting at a time but whada ya do .
The only other thing is check your pc spec , and if you can set your video memory aperature in the BIOS, you may find it at 64 megs well if you can try it at 128 or 256 ...