According to manage network , One of these computers on your home network needs to be designated as an administrator (not to be confused with a Windows Administrator).
Click manage network on the other two computers and check whether you are able to see all three pc’s ? or do we get any one of the following message :
* The computer is not a member of this network.
* The computer is an unmanaged member of this network.
* You haven't been invited to join this managed network yet.