Team Fortress 2 weird display glitch/problem (Pics)

[HipZepi]

I just got a new computer, its my first pc in a while (6-8years) so i don't want to start messing with stuff and f something up

i5 2500k 3.8ghz
8gb ram
Two HD 6870 xfire
1tb hd

StarWars TOR looks great and plays perfectly on the highest settings
Battlefield 3 I have on 'High' and runs perfectly (I was going to try Ultra but i was already blown away by high)
Portal 1 came with the system and it ran pretty much fine except for a tiny blocky glitch on straight lines when i turned side to side fast

- now, i just download TF2 from steam and everything looks fine .. the menus, options, the movie things, every box, window, text, etc.. is fine
but when I enter an online match or single player training I get a really weird spazzy crazy glitch with the graphics. if i stand still nothin happens but as soon as i move everything goes nuts, im seeing thru walls, floors, people and huge block and shapes are glitching out all over the place. its completely un-playable.
- the 'reccomended settings' were what i had first (everything on high), then i tried adjusting the settings and it didnt change anything.

- here are some pictures ::

i tried to take the screen shots without moving too much to show you how it completely spazzes out whenever i move just a tiny bit. you can see everything looks fine except for the environment. and in the online match the other character models and gun models were perfect, but the walls/floors/ceiling/ground/etc...etc... is all messed up.

Anyone have any advice or a solution? I really want to play this game, i love FPS and have heard and seen a lot of great stuff about it. thankyou

 

[Mercenary262]

I FIGURED IT OUT
Steps:
Get latest Catalyst version (above 10.1 at least) I have 11.12
This video artifact error only happens when you try to mess around with the video settings when crossfireX is enabled. So configure the settings you need, apply them, then exit then re-enter the game
After that it should be fine (in theory)