First, unplug the USB cable.
Since you have it plugged directly into comp, you need to make sure you are on the same subnet.
Also it seems like you have access restrictions on the folder which means you would need to log in to the folder using a User that you have created and allowed either read only or read/write access.
If you still need further assistance please provide the following info:
-Model Number
-Firmware verion
-Operating System of your computer
Can the Nas Navi find the unit fine and show a firmware version?