System Software Missing

[redave46]

My lad got a Zumo 665 with the bike he bought recently, all working fine. Last night I connected it to Garmin express for an update, all seemed to go well and when it was finished I turned it off and went to bed. This morning I turned it on and the screen has the message System Software Missing? I've been trying all day to find a way to reload it but Garmin says it's too old for map updates etc, why has the software vanished?

Any ideas on how to get it back muchly appreciated.

Thanks in advance