Windows 7: Three Win7 systems, sharing is spotty.

I have three Win 7 systems on my home network. They're all in the same workgroup, they have identical "Advanced Sharing Options" (File/Printer Sharing on, Network Discovery On, 40 or 56-bit encryption, Password Protection Off, Windows handles Homegroup). None belong to a HomeGroup, just the Workgroup (Workgroup).
One computer can access the other two, one can access one other, and the last can't access either of the others. They all have shared folders with identical share properties ('Everyone' has Full Control).
I'm getting errors stating that some systems can't be found, even though they show up when I open the 'Network' folder. Other errors state that I don't have permissions for particular folders,
I've been in computers professionally for 40 years, and the lack of consistency in Windows networking drives me nuts.
I would like all systems to be able to fully access all systems on the network. Any ideas?

If you can post a screen shot of the ipconfig/all from each machine it would be helpful.

Paste into elevated command prompt>

Actually, two of the three are at a point where I can't capture that right now, but what is it you're looking for? Correct subnets? Same Gateway?
If you can tell me what it is you suspect, I can check it.

I'd need to see the ipconfig's myself if you don't mind.

To capture it all run this command

This will copy all the info to the clipboard and all you have to do is paste it into your reply, Or you could use this command to copy it to a text file