Windows Movie Maker – Black Screen

My computer upgraded to Windows 10 (not by my choice I hate it) It upgraded on its own.

Since then when I go to add videos, it will load them, but my screen is black and no audio. I can see and hear it just fine when I pull it up off my desktop. But when I add it to movie maker won't work. Help please! They are saved in the right format. First time I have ever had problems.

Thanks for any help!