Ok, I've run the wizard again, same result, confirmed that workgroup name is the same.
On one computer I can actually see the other computer but it says "\\XYZ computer is not accessible. The network path was not found"
On the other computer it does not show any computers in the workgroup when I click on it, just comes up with the same error as above.
Both computers have the same IP address?! I ran the ping on both and it seemed to work... but that would make sense since it is pinging itself, right?
I think you're right about comodo, but how do I stop it doing that? I've tried disabling it, but that has not made any difference, I don't really want to remove it because otherwise it is a good firewall, I just want to ensure it allows me to network