winscp will only copy files to and fro, not allow you to maneuver around the filesystem and edit files, what-have-you.

how are you sharing the connection with the laptop? it would seem to me that you would want your own IP address from the router, and using an ssh client like PuTTY you would ssh to the IP address of the n800.

unless you configured key based authentication and did not specify a passphrase in the key, you would be presented with an authentication challenge. i believe the root password (case sensitive) is ROOTME.