So I had a client that couldn’t open email hyperlinks. Whenever you clicked on a email link in Outlook, it would popup a dialogue box and ask what program you wanted to open it with.

The fix… In this case, the registry permissions on HKEY_CLASSES_ROOT\mailto were messed up. I did a right click, and properties and gave everyone full control on the key, and also made the administrators group the owner. I did that on HKEY_CLASSES_ROOT\mailto\shell & HKEY_CLASSES_ROOT\mailto\shell\open as well.

Here is a registry file you can use to recreate the entries if you need to.

Happy emailing!

–Luke