I've had quite a bit of trouble recently with Punk Buster on Windows 7, I know others here have too. There seems to be a number of "fixes" floating about, but none of them worked for me. Anyway, I found a work -around that seems to do the job for me. The instructions are given using CoD4 as an example. They can easily be applied to BF2 or CoD5 etc. Thanks to zaggynl for the fix!