Alright I'll add you :)

I've been playing tf2 for 2 years now with over 2000 hours with this terrible lag and I can't seem to fix it :(
My laptop:-

Name: Packard bell EasyNote TK87
Ram: 4.00 gb
DirectX: 11
Cpu: intel core i5 2.5 GHz
Graphics card: ATI mobility Radeon HD 5470
Windows: 7

This guy http://www.youtube.com/watch?v=dha5HV1QJVw can run the game at high settings with 50-90 fps, and has the same graphics card as me. I have chris config with max frames, I have the razer game booster, I set my windows to look like the old classic windows so I get more performance, my batter settings are set to high performance. I've tried almost everything I found and nothing can seem to work for me. I currently am using all of these and I run tf2 at a fixed 60 fps, but in battles it goes lower than that and it's really unplayable and very annoying, I would really like someone to help me with this issue.

Some things I must point out, my laptop battery is dead, and I'm running my laptop plugged in the whole time without a battery, does that make a difference? Also, my laptop seems to overheat at times so I got a cooling pad, but that didn't seem to make a difference.

-Hossam