at present if a user has left the network and returns it will ask them to register their device again. However if the device has already been registered why can't they just sign in and authenticate as a user. Or is there a way that I have missed.
As far i know, once user has downloaded the prov.exe and executed it successfully for getting connected to desired WLAN then if they return then they shall connect auto as their credential would get cached. no need to extra registration. Let me know if there is something i have missed.