I'm on Win 10 and I've had this issue for a month now, where every time I try to open .c or .v files (or any new file type windows hasn't seen before) it keeps asking me How do you want to open this file? Even if i check that I want to open it every time with Notepad for example it never ever makes it the default. It also doesn't work with other programs like the Windows Notepad. I actually went to the settings and the second I make Notepad the default program it just disappears as a selection and nothing ever happens. I'm pretty sure this would be fixed with a Windows re-installation but I really don't have the time for that and was hoping there was another way of fixing it. This is a video of my experience: https://gfycat.com/AcidicCompetentDeer