This is how to change the priority between multiple monitors.

If you are using multiple monitors (for instant, dual monitors) at home or work, may you need to change the priority between them and make one of them as a main monitor. To do that, you may follow very simple following steps:

Right click on any blank area on your desktop and choose Personalize, then look for Display at the left down corner and press it. On the left upper side menu, select Change display setting. Now you can see your monitors. Just select the one that you want to be your main monitor and check the Make this my main display box. There is also a video which clearly shows the steps.