Three computers, two OS versions, one workgroup, NO permissions (well, it depends)

The workgroup consists of two homebuilts running windows 7; Pro on the big one and Home on the other, and a notebook running 8.1. All are up to date. The pro is hard wired to the router while the others are wi-fi. The network is declared to be work, not home, and all have been verified to belong to the same workgroup by name.

All have shared folders or whole drives, shared with "everybody" (which is my wife and me), no password.

Between the two win 7 machines, Users/Public is available to read and write. But the pro box has no permission to use the shared Home folders and the Home machine has no permission to use the Pro's shared drives and folders.

The notebook is weird. It's C: drive is shared and I can read and write to it from the Pro machine. However, the notebook has no permission to use the shared drives and folders on the Pro machine, same as the behavior of the Home machine.

The Public folder networking is just fine between the win 7 boxes but not there on the win 8.1 notebook. The notebook reads nothing from nobody but I can write to it.

Maybe noteworthy: a homegroup on the Pro box was recognized by both the Home machine and the 8.1 notebook but neither could join it. That's why I went the workgroup route but that's not working, either.

What am I doing wrong, here.