Not True,,
Configuration is the key,, ensure all the PC are in the same scope, Net mask, gateway, Workgroup, etc,, and you will do fine,,,
A router is just a smart box that is more precise in connecting PCs,,however, if you are not in that "neighbourhood" ,, the router will block your transmission,,
and will give you some of the errors that you mentioned,,
research the instructions, and do a good job
cheers,