So i wanted to change my resolution .. then when i change it example from 1247X746(not sure about the number) to 800X600 it lags and it says DirectX unrecovarable blah blah blah.. I tried to reinstall still not working.

 

Tnx, Alfihz.

 

P.S: i have a graphic card ATI radeon hd 5450 .. and have the latest DirectX 11

Here is a different way to change your resolution.

 

1. Go to your MW2 folder. Now, go to the /players/ folder inside your game folder.
   
2. Open up config_m2.cfg with Notepad.
   
3. Hit CTRL-F and type in 'r_mode' (without the '').
   
4. Change the value a space after r_mode to '"800x600"
   

Make sure it's valid resolution as well. (You could also try using r_fullscreen 0, vid_restart, then change your resolution.)