Books not downloading

I've had multiple issues with my new digital editions 4.5, usually if I just uninstall it and then reinstall the problem is solved. My issue is I will download books from netgalley but then they won't upload to my digital editions. I've changed the .acsm files to accept digital editions previously but this time when I reinstalled the 4.5 edition it doesn't give me that option to make it the default program. I'll even go to browse programs, find digital editions 4.5, double click to save it and it doesn't work. It 'automatically' saves it to an adobe acrobat reader dc which doesn't accept the .acsm files.