Thanks Ratandeep.
Unfortunately those don't apply to my situation. I think if I make you understand what is happening it will help you point me in the right direction.
This is an old backup of several folders from a Windows 7 computer.
The backup is stored on a file server.
I am now testing with 3 laptops on the network, all running Windows 7.
I start the Windows 7 backup application and choose "select another backup to restore files from."
I then browse the network to the path where the backup is stored on the server. For example: \server\backup
The backup is loaded and I can browse/search for files and folders.
I choose a file at random and select "in the following location" to restore the file to a folder on the laptop I am testing with.
This process works fine on 2 test laptops, but FAILS with my main laptop. THAT is what I have to fix. It seems the problem is on the laptop, not the server, and not a problem with the backup itself.