how to change window width

So I am finaly able to launch this, I am using a window layout of 2 screens running 2 accounts on WoW but the windows seem to be way too wide the center screen window goes half way in to the right monitor and the right window goes way out of the monitor.

ok so I got this figure out, it was scaling that was causing too wide of a screen. Now I have the problem that if I click on anywhere on the middle screen/window it just swaps with the right window/screen.