Unexplainable TF2 lag on good rig

[Existence.]

Hey everyone,

Lately, when I play TF2, I get maybe 20 FPS average, dipping down to about 10 when I'm in a firefight. It's never been like this, just after I went from XP to Windows 7. However, before when I had Windows 7 (When it was first released), I didn't lag.

I can play Fallout 3 high, Crysis medium, and even Left 4 Dead with everything high at 1440 x 900 without any lag whatsoever, but when I play TF2, I lag a lot.

One thing I've noticed: Whenever I'm playing any graphic-intensive game, my CPU is always around 90-100%. And, my video card is barely (20-30%) being used.

I have an ATI Radeon HD 4670 1GB video card, 6GB or ram, an AMD 3800+ X2 CPU, and Windows 7 beta X64.

Any help is appreciated,
-Existence.

 

[NUFAN]

What about other source/orangebox engine games?

 

[LightHunter]

if you have windows xp or vista backed up try it on that and see if its any better. also it seems like your graphics card isnt at its full potential. whats youre Ghz?

 

[HardHat]

Run Furmark and monitor the core/memory speeds and temp. It might be throttling down.

 

[Deimos]

Do you mean 4870 1gb? Do you have the latest drivers/have you tried re-installing them? And do what HardHat said, check the speeds on your card

 

[Existence.]

NUFAN: Other Source/ Orangebox games don't lag, just TF2.

LIGHTHUNTER: My CPU is 2 GHz overclocked to 2.1. My video card is 750 MHz core with

HARDHAT: Nope, the speeds are staying the same, not throttled.

DEIMOS: Nope, I mean the Sapphire Radeon HD 4670 1GB video card. And, I have tried reinstalling the drivers. But, if I ONLY lag with TF2, I didn't think that would solve it.

Also, I'm almost positive its a CPU issue, not a videocard issue.