Garmin Nuvi 44LM

This Garmin 44LM is stuck at the Garmin logo screen.  The user had it connected to their laptop and accidentally encrypted it with Bitlocker.  We have the decryption key, but since encryption it don't go past the boot up screen.  Tried factory resettinjg but that didn't work. Perhaps my factory reset procedure is incorrect - I found conflicting instructions.  Please let me know how I can recover this GPS.  Thank you.