Graphics Won't Switch!

So whenever I load up WoW WOTLK (The new version) and try to change the graphic setting to the highest quality (1920 x 1080 [Wide] ) it instead stays the same and when I minimize the window shows a ghost version of the game in the top left of my screen, making it impossible to do anything in that 1/4 of my monitor. I have tried changing the properties on the file but everytime I switch the [Read Only] property to off it just stays the same. I have been fighting this problem for about 3 months now and was wondering if anyone had any idea how to fix it, and yes, my computer can run at the highest quality (1920 x 1080 [Wide]).