I'm trying to network a nearly-new Optiplex 3050 ("PC-A") with brand-new PC ("PC-B"). The Dell will let me in to shared folders on PC-B but attempting the reverse is a nightmare. PC-A icon does show on the desktop of PC-B but any attempt to open it returns "Windows cannot access \\PC-A". "You do not have permission to access \\PC-A. Contact your network administrator to request access". Well I'm the administrator, I've asked him, and he's stumped

This goes way deeper than incorrect sharing settings, which I've quadruple checked of course. I've set various folders to be shared by "everyone", even at top C: level (which it wasn't keen on letting me do, understandably). I've tried all sorts of tips and tricks from the internet, including registry and services tweaks, but nothing will let me in. Except... almost by accident I found that typing the full path of a folder into the Explorer address bar (eg \\PC-A\USERS) will open it up.

I mapped that path to a drive letter, so it does now give me some inflexible access to that drive. But it's still not right.

Now the next problem. PC-B cannot see the printer attached to a USP port on PC-A. It doesn't seem to exist. Typing a pathname \\PC-A\printername doesn't work, although typing the same into PC-A brings up the printer's main window. This is no great surprise as PC-A still won't let PC-B in at the top level.

These machines are almost identical. Both run the same version of Windows 10 Pro (v1809, build 17763.437). All network and sharing settings are the same, as far as I can see.

So... how do I get full access to PC-A from PC-B? How do I get to use the printer? The number of similar cries on the internet suggests this is a common problem in various guises. It beggars belief that Microsoft should release software that can't perform the basic job of networking two computers properly. Bring back XP, I say.