Multiple monitors

Hi, my question is not about challenge but I have no place for my question. Please, be indulgent. i work with people with disabilities.

I use two monitors with one PC. I have 4 PC and 8 monitors. I want to have 1 application=1 monitor.

When I launch for example PowerPoint diaporama on monitor 2 and nothing in primary monitor: all is OK But if I launch in the same time another application on primary monitor, the diaporama stops.

I need a solution for forcing the application to work on monitor 2 all times.

Thank you