How big are the servers you are playing on? Sometimes you might need to drop the graphics on something like that. I mean, I don't think you'll notice a HUGE difference if you set some of the other settings to medium or so, if they are all on high I assume. I do mean setting them to medium (or whatever step below what you currently have) as in, set the graphics down to the area that affects you. So if its outside, trying dropping the lighting and other 'outside' textures that would affect it.
Originally I was going to say scan for trojans, viruses, and spyware if you haven't already, but I presume you have. Also, try defragmenting, that worked a while back for me when BF2 was acting up. Of course, you are on a newly formatted HDD. I don't know, try doing all of that anyhow if nothing else works. Sometimes on a fresh install you could skip an update here or there and be VERY vulnerable. I always get the Windows Updates first and I have all my anti-virus/spyware/adaware programs on an external HDD which I install right after all the Windows Updates before I even touch the internet. Then I scan with all of them even on the fresh install and make sure everything is secure. Then I start using the computer normally; haven't had any problems using that procedure yet.