For Windows 10, change these keys in regedit
:
Computer\HKEY_CLASSES_ROOT\SystemFileAssociations\text\shell\edit\command
Computer\HKEY_CLASSES_ROOT\SystemFileAssociations\text\shell\open\command
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\batfile\shell\edit\command
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\cmdfile\shell\edit\command
From: %SystemRoot%\system32\NOTEPAD.EXE %1
To: "%ProgramFiles%\Sublime Text 3\sublime_text.exe" "%1"
Or: "%ProgramFiles%{insert-path-to-fave-editor}" "%1"