Actually there are still two Win7 computers among the six, so just four Win10. But lets ignore the new Surface Pro Go for now since I don't even have it fully configured yet. So that leaves just three Win10 PCs to deal with for now.
On the most important of them, DELL-DESKTOP, I was able to find SMB 1.0, un-check it, and re-boot. However, when I rebooted I got three successive error messages, complaining that WDBackupService, LogTransportService, and LogTransport2 could not be loaded.
I was unable to find any SMB 1.0 on the other two Win10 PCs. I suppose that amounts to the same thing as un-checking it if it had been there,
Incidentally, all three Win10 PCs had different dialogs for Windows Features. On one of them, for example, all I could find was one entitled Optional Features, which appears to be the same thing.
On the bright side, it's hard to be sure since there are so many permutations, but there does appear to be an overall improvement in the ability of the two Win7 PCs, PEYTONS-SYX and PEYTONS-SYX2, to be able to access each other and the Win10 PCs, and be accessed by them.
Except that only DELLTOWER can even see CYBERPOWERPC at all, though it still sees it as VIF8U6B.
The remaining shortcomings of PEYTONS-SYX, PEYTONS-SYX2, and CYBERPOWERPC may have to do with the fact that they used to be all on a Homegroup. Can I just get rid of this Homegroup? How?
Thanks for your continued help.