You can do it with the registry approach but it is unreliable is unreliable in Windows 8.1 onwards and you should really use the Win32 API calls to AssocQueryString.
Dave
-----Original Message----- From: ProFox [mailto:profox-bounces@leafe.com] On Behalf Of Alan Bourke Sent: 28 March 2017 16:32 To: profoxtech@leafe.com Subject: Re: Default application for shellexecute
http://fox.wikis.com/wc.dll?Wiki~AssocQueryString