Network sharing broke after working many years OK

File sharing is broken on my computer network. It has worked fine for many years but has become broken the last week. For some computers it continues to work OK. For others it either works intermittently or not all.

Now some computers after booting will share OK for a few minutes but then stop sharing to certain computers.

Note even if I double-click on a computer shown in File Explorer > Network it makes no difference. It will simply time out.

I tried resetting the networks on D1 and L1 but it made no difference. I also rebooted the modem/router.

It is normal for me to access my network computers using shortcuts. That has always worked even when the computers don't show up in File Explorer > Network.

Note I use the same username/password local account on all my commuter accounts. They are all of type administrator. All shared folders have read/write write permissions for this account on all my computers.

This is very important to me for the following reasons:

• The main computers affected, D1 & L1, are my daily use computers.
• D1 serves as a repository/archive for all my computers.
• The backup drives for L1 and L2 are connected to D1. Automatic backup fails when a network connection can't be made.

Network computers

Desktop computers
D1. Darkmatter - Windows 11 Pro
D2. Lightning - Windows 11 Pro
D3. Phoenix - Windows 10 Home
Laptop computers
L1. Starship - Windows 11 Pro
L2. EventHorizon - Windows 10 Pro

Tests done to see if I could access computer shares

D1 > D1 - Sharing OK
D1 > D2 - Sharing OK
D1 > D3 - Sharing OK
D1 > L1 - Sharing stops after a few minutes
D1 > L2 - Sharing OK

D2 > D1 - Sharing stops after a few minutes
D2 > D2 - Sharing OK
D2 > D3 - Sharing OK
D2 > L1 - Sharing stops after a few minutes
D2 > L2 - Sharing OK

D3 > D1 - Sharing OK
D3 > D2 - Sharing OK
D3 > D3 - Sharing OK
D3 > L1 - Sharing OK
D3 > L2 - Sharing OK

L1 > D1 - Sharing stops after a few minutes
L1 > D2 - Sharing OK
L1 > D3 - Sharing OK
L1 > L1 - Sharing OK
L1 > L2 - Sharing OK

L2 > D1 - No sharing
L2 > D2 - Sharing OK
L2 > D3 - Sharing OK
L2 > L1 - Sharing OK
L2 > L2 - Sharing OK

Click to expand...

Were any of the network computers set up by cloning / imaging other computers?
If so, see para 1 of A consolidated network setup checklist for Windows 10 and 11 - my post #4 - TenForums

Denis