Home/ Questions/Q 6353303
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-24T22:23:15+00:00

OK, it might be a problem with my system but I’m having a very

  • 0

OK, it might be a problem with my system but I’m having a very difficult time getting Windows 7 to recognize my custom exe as the default handler of the mailto protocol.

First, I’ve seen this:
Register Windows program with the mailto protocol programmatically

Next, I’ve seen these:

I’ve added what seemed the appropriate registry entries but I still get Windows Live Mail coming up every time I click a mailto link (whether in a browser or via the Run window). I’ve set the registry entries for all users and for the current user, still it doesn’t work.

When I go to the ‘default programs’ app and scroll down to the mailto protocol, I only see Outlook and Windows Live Mail listed. My custom app doesn’t even appear.

I figure that it’s either something special with Windows 7 or it’s something with my computer.

My custom app is a WinForms .Net app but I don’t think that matters.

Any ideas are greatly welcome.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    The way described in the answer which you referenced in your question seems correct way for Windows 7 as for other operation systems.

    I suppose that you use 64-bit version of Windows 7 and your program is 32-bit application. So if your application write in the HKEY_LOCAL_MACHINE\SOFTWARE\Classes\mailto\shell\open\command key it modifies only the key HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\mailto\shell\open\command used for 32-bit applications. You can read more about registry virtualisation here and here.

    If it’s your case you can call directly native Win32 API RegOpenKeyEx with the KEY_WOW64_64KEY flag which will be ignored on 32-bit operation system.

    • 0