The Network access maintain a list of network connection. You define here the access to a network folder.
The network access is used to establish the connection with a remote computer.
It is no longer necessary to define the network connection for each backup set. You have to pick the folder in the list. To access the list click the 
button available near each folder definition. If this button is grayed this means that you don't have define network access.
The selected folder must be defined in an UNC file format (\\computer\folder...) and not in a mapped drive format (e.g. Z:\). Mapped drive are unknown when the user is not logged, so scheduled jobs will fail.
To change a network access definition pick the definition in the list using the button.
