How to Browse the Windows Store from Win8.1
You need a Microsoft account to get anywhere beyond basic searching. If you logged on to Windows with a local account, the Microsoft account requirement splats you right in the face.
If you decide to use a local account but need to sign in with a Microsoft account to get updates or new apps from the Windows Store, set up a bogus Microsoft account and use the facility offered to sign in to each app separately. That way, you’ll be warned before you venture into another location that requires a Microsoft account.