Associations are basic (ok, medium) Windows skills. The old re-association noted at http://www.sevenforums.com/tutorials/19449-default-file-type-associations-restore.html should help.
Then you can change the default browser again. This does occur when browsers update. It is not a bug.
Bob
When touching the icon, the message "Unable to open this internet shortcut. The protocol "https" does not have a registered program."

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