This tutorial will help you reset any metro style application, this includes Cortana and Microsoft Edge
Open Windows Explorer (Windows Key + e)
Navigate to C:\Users\<username>\Appdata\Local\Packages
Shortcut: Type %LOCALAPPDATA%\Packages in the address bar
The folders should be in the format Publisher.Application.ID locate the folder for the application you wish to reset, right click and rename it. I tend to just append .old
Open an elevated powershell prompt (Press Windows Key, type powershell, right click "Windows Powershell" and select Run as Administrator