Change default mail client windows 10 registry

A geeky question!

To change the default mail client in Windows 10 using the registry, you'll need to modify the following registry key:

HKEY_CLASSES_ROOT\mailto\shell\open\command

Here's a step-by-step guide:

1. Open the Registry Editor: Press the Windows key + R to open the Run dialog box, type regedit, and press Enter.
2. Navigate to the mailto key: In the Registry Editor, navigate to the following key:
   • HKEY_CLASSES_ROOT\mailto
3. Modify the shell key: Right-click on the shell key and select Modify.
4. Change the default value: In the Value data field, enter the path to the executable of your preferred mail client, followed by the command-line arguments. For example:
   • For Mozilla Thunderbird: C:\Program Files\Mozilla Thunderbird\thunderbird.exe "%1"
   • For Microsoft Outlook: C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE /mail "%1"
5. Click OK: Click OK to save the changes.
6. Verify the changes: Close the Registry Editor and open a new Command Prompt or PowerShell window. Type mailto:[email protected] and press Enter. Your default mail client should open with the email composed.

Important notes:

• Make sure to replace C:\Program Files\Mozilla Thunderbird\thunderbird.exe and C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE with the actual paths to your mail client's executable.
• The %1 placeholder represents the email address that will be passed to the mail client.
• If you're using a 64-bit version of Windows, you may need to modify the registry key for the 64-bit version of the mail client. For example, if you're using 64-bit Thunderbird, the path would be C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe.
• Changing the default mail client using the registry may not work if you're using a third-party mail client that doesn't support the mailto protocol.

Remember to be cautious when modifying the registry, as incorrect changes can cause system instability or errors.