I've run into a frustrating issue where two Windows 11 computers on our server domain can't access each other's shared folders. Specifically, PC A can share its folder, but PC B gets repeatedly prompted for credentials that don't seem to work, regardless of whether they're Active Directory users or local users. The same issue happens in reverse: PC A can't access PC B either, with the same credential problems.
Here's what I've tried:
- Created new local users for access
- Tried accessing PC A using both its name and IP address
- Adjusted the NTFS security settings
- Quit and rejoined the domain
- Changed the computer name and/or IP (including release and renew)
- Disabled and re-enabled the share, and even shared a different folder on another drive
- Accessed with a different account, even logged in as a different user on PC B
- Restarted machines multiple times (including clearing unstable BIOS settings)
Despite all these attempts, I still can't get them to communicate. Any ideas or suggestions would be appreciated!
3 Answers
Are you running these on Windows 11 25H2 and have you applied the October updates? I've faced similar problems in two offices since those updates hit. It turns out that any combination of Windows 11 25H2 and older versions doesn't interact well. If you've already checked for duplicate SIDs, then it sounds like a similar issue.
Just a heads up: if SMB1 is disabled across the board, everything should be using SMB2 or higher. Have you confirmed that all settings align with that requirement? Sometimes, lingering settings can throw things off. Also, check the firewall rules—make sure file sharing is allowed between devices.
Definitely worth checking! I've seen firewalls block connections surprisingly often, even when everything looks good on the surface.
You might be dealing with duplicate SID issues, especially if the machines were cloned or recently updated. Check this Microsoft support article on Kerberos and NTLM authentication failures due to duplicate SIDs for some insights. It might help identify what's going wrong with the authentication process.
How would duplicate SIDs affect access? Would it last even after a computer is renamed and rejoined to the domain?
Good to know! I know it sounds unrelated, but I've considered rolling back to a prior version or even switching to Windows 10 to see if that solves the issue.