Team Fortress 2 doesn't work well with Windows 7. It almost seems it creates a limit of preformance/power in the background for the game. No matter what resolution, video settings, etc. It will still lag when many things/people are going on in front of me. I even made my TF2 look like Quake. Which is pretty sick.
and it will still lag. But it's playable still, I guess.
It's not my computer, since it worked well with Vista and XP.
But ya, PunkBuster is crap. I wish they would find something, or make them improve PB.