UNC path shortcut fails after disabling/re-enabling SMB 1.0

Question

I have three computers on my home Ethernet (i.e.. Cat5e wired) as follows:

DELLDESK Windows 10 Pro, 21H2
OPTIPLEX Windows 10 Pro, 22H2
LAPTOP2 Windows 11 Pro, 22H2

On the desktop of each computer, I have shortcuts so that I can access the Shared folders on the other machines. For instance, on OPTIPLEX, I have two shortcuts pointing to \DELLDESK and \LAPTOP2. All of these shortcuts were working correctly.

As an experiment, I disabled “SMB 1.0/CIFS File Sharing Support” from Windows Features (I’d heard that SMB 1.0 is unsafe) on all machines. Afterwards, one of the desktop shortcuts no longer worked (all others were still working). Specifically, the OPTIPLEX desktop shortcut pointing to LAPTOP2 fails with the following error:

Network Error
Windows cannot access \LAPTOP2
You do not have permission to access \LAPTOP2. Contact your network administrator to request access.
Error code: Error code: 0x80070035
The network path was not found.

I have now re-enabled SMB 1.0 on all machines, and rebooted, but the situation remains: all shortcuts work except the one from OPTIPLEX pointing to LAPTOP2. Clearly, disabling SMB 1.0 has had a very specific side-effect that has not been reversed by re-enabling SMB 1.0. What could that possible be?

Answer 1

I discovered that I can access individual folders on LAPTOP2 from OPTIPLEX. For example, a shortcut with target, \LAPTOP2\Personal works.

I looked at the Local Disk (C:) Properties on each machine – File Explorer > Right-click Local Disk (C:) > Properties. On the “Security” tab there is a list entitled, “Group or user names:” and a panel below that, which gives “Permissions for users”. The following users are listed on all machines.

Authenticated Users
SYSTEM
Administrators (ComputerName\Administrators)
Users (ComputerName\Users)

On all computers, the following permission are allowed (there are no denials) for each group or user name:

“Authenticated Users”:
o Special permissions

“SYSTEM”:
o Full control
o Modify
o Read & execute
o List folder contents
o Read
o Write

“Administrators (ComputerName\Administrators)”:
o Full control
o Modify
o Read & execute
o List folder contents
o Read
o Write

“Users (ComputerName\Users)”:
o Read & execute
o List folder contents
o Read

On LAPTOP2 there is an additional item:

“Account Unknown(S-1-15-3-longSeriesOfDigitsAnd Dashes)”
o Special permissions

When I look at the Special permissions for this item, I see that the owner is “TrustedInstaller”. Perhaps this item is a leftover from the fact that LAPTOP2 is a Dell Certified Refurbished that came with Windows 11 Pro pre-installed.

Apart from this extra Group/user item on LAPTOP2, I see no discrepancy between the machines. Really don’t know where to go from here.