When I first started doing the groundwork for this article I incorrectly assumed that the default mail client was a setting that each user could change in Windows.
What I mean is - I thought if ‘USER A’ logged in, set the default email client…then ‘USER B’ could login to their account and set their own default email client.
After testing many different ways I have found that it does not work this way at all.
If you are not an administrator, windows will gladly let you go into the internet settings under the control panel - and make the change:
Unfortunately it does not give you an error. If you go back into the settings, it will have reverted back to the original default email client.
This is because the setting is located in the HKEY_LOCAL_MACHINE hive of the registry, and there is no corresponding HKEY_CURRENT_USER entry. If you create one on your own, windows will simply ignore it.
Here is the key for setting the default email client:
HKEY_LOCAL_MACHINE\Software\Clients\Mail
If you drop down to this in the registry, you…
