Networking issue between 2 desktop & laptop

So without being too hyperbolic, I'm about to die!

I've spent too many hours with 0 progress and am beginning to resent pcs in general.

I have 3 pcs (2 desktops and a laptop) all wired via gigabit.

In short - my desktop (a) can see itself and my laptop under network, but not the other desktop (b).

My laptop can see itself and my desktop (a) but not the other desktop (b)

My other desktop (b) can't see itself, but can see my desktop (a) and my laptop.

All I've come up with so far is the miserable reformatting of my desktop that presumably is the key to the issue (b).

A few things happened after such that may point you networking geniuses in the right direction.

A) it showed up on the network immediately after a fresh Windows install.

B) it disappeared after I changed the name.

C) I got it to show up spontaneously after a full shutdown (not restart) but may have been coincidence.

What happened next was this - upon restarting either the laptop or desktop (a) it continued to see itself and the others continued to see it. After restarting desktop (b) itself - it once again no longer saw itself nor did the others see it.

Further shutdowns/restarts were fruitless. Also rebooted both router and switch.

I'm at a loss, yet ocd enough to not move forward with anything until I fix this.

Learn me sum networking101!

Oh I forgot to add, they can see plex media server if it is running on the desktop (b) and if I type in the address they can reach the Desktop (b) and browse it just fine.

Simply nothing shows in explorer

Just give it a try..
Reboot in safe mode with networking with one of the non working PCs and see if you are able to see it now on other computer.

Okay will try safe mode and see what happens. Will report back!

In safe mode with networking nothing shows up on any of the pcs

Okay I have some new info which is odd and I'm not sure if it's relevant or not.

1) desktop A and desktop B can ping one another.

2) desktop A and desktop B cannot ping the laptop

3) laptop can ping desktop A and desktop B

4) both desktops are on the newest version of win10 - the laptop is on a slightly older version of win10.

5) to reiterate, nobody can see desktop B in file explorer but if navigated to via address it can be browsed.

Hope this helps...

Also when I do a net view via cmd i get an error 6118 if that helps?

Sheeee What a mess.......
Change Network location to Private in place of public and see if that helps.
1. try disabling the firewall and see if that helps.
2. Try to create a homegroup on desktop and see if other computers can connect with it.
3. In your router try to reserve IP addresses for all 3 of your computers and see if that Helps.

Have they all got the same IP range and subnet is all on 192.168.1.? Are you using home group or normal network? Open a cmd prompt on one of type ipconfig /all then post results

I'll learn my lesson eventually.

After dumping all pcs and doing my main pc last, somehow it was the culprit. A product of a "remove telemetry" app that removed the browser service completely.

Jesus I'm decidedly going much more conservative this time. I'm exhausted with reformatting

Now the only issue is I changed a pc name when I reformatted and the old name as well as new name is showing up in network.

I can't seem to win.