cant change my resolution stuck at 1440 by 900
 

i try to change it in game and it says needs restart which I do and keeps coming back to 1440 by 900 , also I turn off shadows and still get shadow fiickering, I fought my first battle on the world map on a quest and the lag was so bad I had no idea how to get troops together because of lag and was crushed, the main thing is how do i change my resolution , is this a bug or do I need to change my desk top res