I was using Windows Live Mail and Skype under Windows 7. After upgrading to Windows 10 I lost Skype. I had to re-install skype via the Windows 10 Upgrade Skype. That required an Outlook.dk account. After setting up an Outlook.dk account the Mail tile now only opens Outlook.dk. 

How to I get my Windows Live Mail (WLM) back?

It is important that I do not loose my WLM storage, settings and accounts. I use a POP3 account that I no longer have the user name and password for.