Create Safepoint can't locate my computer with external drive

I am trying to create my very first Safepoint and initially attached a shared 3TB external drive to a Windows 7 laptop connected over wireless.  The Discovering Devices phase of the Create Safepoint located the drive and I was able to start the backup, however it estimated it was going to take 3 days to backup 1.8TB.  I decided to connect that external drive to a desktop computer, running Windows 8, that has a wired connection to see if it will backup faster.  The external is once again shared from that computer, but this time Discovering Devices does not display that computer.  I tried turning off the Norton Internet Security firewall, changed various network settings, changed the permissions on the shared drive to full read/write access to Everyone.  I can see the shared drive/directory from all other computers at my house, but the Create Safepoint process never displays that computer.  

Is there a particular setting or characteristic that Discovering Devices is looking for that I need to set on this computer and/or shared drive in order for it to be located?  Another odd thing is that everytime I click the refresh button to restart the Discovering Devices it always gives me different computers on my network.  It doesn’t always locate the same ones, but it always misses the one I am working with. 


Check the link below so you can review the steps to share a folder on your network.