Back up folder on NAS to local HD (autop sync the folder)

[Kanalua]

My wife has a folder on the NAS that she access from her laptop and the desktop. I was wondering how to automatically do a backup of the folder on the NAS to a location on the laptop's local HD (in case she needs to access the folder while off site - and off the network - on the laptop).

NAS is Synology DS108j and laptop runs Win7 64 home premium.