Setting windows on 2 monitors

I have a few systems with 2 monitors. If I open my browser and move to second window, subsequent browsers keep opening in second window. Sometimes if I move back to first screen, the next window will open on 1st screen but sometimes second. How do I set the positioning?

Also I opened Powerpoint on second screen, then did full window, now all powerpoints come up on second screen, and I a cant find any setting to change that as well
thanks for any help