@Butters, thanks for your response. the thing is I formatted my device (using RMPrepUSB) without double checking if my old backup still available. unfortunately I cannot find the backup in every USB flash-drive I have, it might be hiding somewhere or I already lost it. GarminExpress now is not recognizing my device as there is nothing running on the device. I could only access to my device via so-called mass storage mode (i.e. as USB storage). Thus I thought of someone here might have a copy of the backup for the same device, so I could copy it to mine. or there is another way to fix it?