Programatically change the programs associated with a file extension in Windows
https://ss64.com/nt/ftype.html https://ss64.com/nt/assoc.html https://www.emacswiki.org/emacs/WThirtyTwoFileAssociations To use the emacs client as the editor associated with certain file extension, use the ftype and assoc commands. Run the followin as admin: ftype Emacs.org=<emacs-path>\emacsclientw -na runemacs "%1" ftype Emacs.el=<emacs-path>\emacsclientw -na runemacs "%1" rem ftype txtfile=<emacs-path>\emacsclientw -na runemacs "%1" assoc .txt=txtfile assoc .org=Emacs.org assoc .el=Emacs.el To add the option to open a file with emacs, edit the following registry file, substituting the .el extension with one you want to open with Emacs, and import in regedit:...