How do you delete a file association in Windows 8.1? All the guides I've found seem to only work in Windows 7 or below, and Control Panel > Programs > Default Programs > Set Associations doesn't have a delete option. Is there a particular registry key I need to edit/remove?
One hack that can be used to achieve this end is to create a file in desktop with .exe extension, associating the file type that you aim to disassociate to that new program that you created (Which can be just a text file renamed to .exe)
This way now your program is the one responsible for opening the file, if you now delete that exe file, next time you open this file type you get an option to choose again (as if nothing existed).
The registry keys to delete is in HKLM\Software\Classes and then search for the file extension if it is associated with another class delete that class as well, however if you are not used to regedit I would recommend the prior approach.