I need help with a rather complicated problem. Please bear with me.
I run a Verizon Fios Internet router, model G-1100. I have 2 Windows 10 PCs and a variety of other Ethernet devices, all connected to the router (and to each other) through a Netgear unmanaged Gigabit Ethernet switch. I went to this setup because I needed more bandwidth than was afforded by the router's wifi. I experimented with a TP-Link Range Extender, and finally with a TP-Link Gigabit powerline adapter, to which I connected my PCs. When that proved not fast enough, I went to the Ethernet with a single CAT 6 cable from the switch to the G-1100. This all works great. Both PCs enjoy very high throughput - ~ 1 Gigabit up and down.
However... the one thing I cannot do is to share files between the two PCs. When I look at the network from the Taskbar icon on my primary computer, it says that the network is "TP-Link_DO89_5G_2", which is the name of the powerline adapter, which is no longer in service. The devices listed include a big TV, a couple of Rokus, and my printer, which is not on Ethernet, rather is still running off the router's wifi.
Note that my second PC does not show up in this list, nor do a lot of other devices. So now I go on my second PC, and look at the list of network devices it sees. It is the same list, exactly, and it does not show my primary PC either. When I click on the Ethernet icon on the Taskbar, it displays the connected network as "Smith", which was my network name before all this change happened.
One final trimming - when I access the router it displays my system in two categories - Primary Network, containing only the big TV, which is cabled by Ethernet directly to the router, one Roku (I have 2), and my printer; and another list, accessed by a "Show More" prompt, which includes ALL the rest of my devices, including both PCs.
So after all that my question is simple: how can I clean up this SNAFU, get all my PCs and devices on one network, and be able to transfer files between the PCs as needed.
Simple things to start with.
Can you ping from one PC to another?
You say they are on different networks.
But are their IP addresses on the same subnet?
Have you tried to delete networks on PCs and rediscover?
Situation now: I can ping each machine from the other. They are on the same subnet. I've made a little progress (I think) since my last message. I reset the Ethernet adapters on both machines. The primary computer now sees the secondary machine on File Explorer, but the secondary computer just sees itself and not the primary. If I double-click on the secondary computer's icon in File Explorer on the primary machine, I am told "\\NEW-SKIMMER is not accessible. You might not have permission to use this network resource..." I am logged on with Administrator status, so I don't know where to go from here.
One additional datapoint - When I click on the Ethernet icon on either machine's Taskbar, they both say they are connected to network Smith. That is a network I originally created months ago for wifi, but I have not knowingly connected either machine to it using Ethernet. Could it be that there's something stored on the Verizon router that is responsible? If so, what to do?