Here are the links for creating a separate alias for login:
Create an alias for login purposes only. Designate this alias as the primary alias at:
https://account.live.com/names/manage
then disable sign-in capability for the other aliases here:
https://account.live.com/SignInPreferences
You can still send and receive email from the old address. Keep the new alias secret. Do not use the new alias for anything except login.
When someone tries to login to your account, they will receive a message that the username does not exist. They can't hack your account if they don't know your username.
Be careful to not REMOVE your email address at the first screen. There you only want to create the new alias (click on add email) then make the new alias Primary (click on Make primary, NOT Remove).
