Make Musescore 2 a default app on PC
I've spent the last few days figuring out how to run Musescore 2 as a default app on a PC after I downloaded Musescore 3.
It appears to me that if Musescore 3 is installed, Musescore 2 cannot be a default app.
Uninstall both versions of Musescore. Download Musescore 2 again from https://musescore.org/en/download#Older-versions
Then go to settings, default apps, choose default apps by file type, and set .mscx and .mscz to Musescore 2 (You'll notice that if Musescore 3 was on your PC, it will still have the icon even if the programme was unninstalled). Musescore 2 does not appear to present as an option if you have not uninstalled and reinstalled it again. I've done it twice this way and it worked both times. If this doesn't work for you, you'll need to find someone else for help.
Don't reinstall Musescore 3 if you want Musescore 2 to be your default app.
Musescore 3 is fantastic and I will download it again. It's just that right now I need Musescore 2 for a technology exam and the slightly different interface is adding an unwanted variable to an exam scenario for my students.