Inconsistent Shared Folder Access Across Hospital Systems - Microsoft Support Request

Question

• Unable to access shared folders (e.g., <Server-IP>\Share) from some client systems; Windows Security prompts for credentials repeatedly.
• Other systems access the same share seamlessly without prompts.
• Troubleshooting attempted: Disabled password-protected sharing, verified NTFS/share permissions ("Everyone" read access), added credentials via Credential Manager/net use /persistent:yes, checked Local Security Policy (Classic model), restarted Server service. Issue persists selectively. these all the trouble shoot done.

Answer 1

Thank you for your prompt update and confirmation, Issue has been fixed @Domic Vo We're glad to hear the issue has been fully resolved following the mirroring performed with the bulk purchased system by the vendor.

Answer 2

That sounds like it may involve the duplicate SID problem. Please see my prior post here-

https://learn.microsoft.com/en-us/answers/questions/5648842/latest-win-11-updates-have-enforced-sid-and-now-i

Answer 3

Hello govindharaj.t,

From your description, the repeated credential prompts on certain clients while others connect seamlessly indicates that the issue is not with the share or NTFS permissions, but with how those specific clients are negotiating authentication with the server. Since you have already disabled password-protected sharing, verified permissions, and tested Credential Manager, the most likely cause is a mismatch in authentication protocols or cached credentials on the affected machines.

Windows file sharing relies on SMB, and depending on the client configuration, it may attempt NTLMv1, NTLMv2, or Kerberos. If the server is enforcing NTLMv2 only (HKLM\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel set to 5), but the client is still attempting NTLMv1, you will see repeated credential prompts. Check the registry on the problematic clients under HKLM\SYSTEM\CurrentControlSet\Control\Lsa and confirm that LmCompatibilityLevel is set to at least 3 (send NTLMv2 response only). After changing, reboot the client.

Another common cause is that the client is attempting to connect using its local account context rather than the proper domain or workgroup account. Even if you add credentials in Credential Manager, if the format is not SERVERNAME\username or DOMAIN\username, the authentication will fail. Test explicitly with net use \\<Server-IP>\Share /user:<ServerName>\Administrator to confirm.

Also verify that the affected clients are not using cached incorrect credentials. Run cmdkey /list and remove any stored entries that point to the server, then retry.

Finally, check SMB signing requirements. If the server has RequireSecuritySignature enabled in HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters, but the client does not support or has disabled signing, authentication will fail. Align the settings by ensuring both server and client have EnableSecuritySignature set to 1, and RequireSecuritySignature set consistently.

In summary, the selective failures are almost always due to authentication protocol mismatch or incorrect credential context. Adjust LmCompatibilityLevel, clear cached credentials, and confirm SMB signing alignment. Once these are corrected, the affected clients should stop prompting and access the shares like the others.

I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message. Have a nice day!

Domic Vo.

Answer 4

It sounds like you're experiencing a frustrating issue with inconsistent access to shared folders across different client systems. Here are a few potential areas to investigate based on your description:

1. Network Discovery and File Sharing Settings: Ensure that network discovery and file sharing are enabled on all client systems. This can be checked in the Control Panel under Network and Sharing Center > Advanced sharing settings.
2. SMB Protocol: Since some systems are accessing the share without issues, verify that the SMB protocol is consistently enabled across all systems. You can check this by going to Control Panel > Programs > Programs and Features > Turn Windows features on or off, and ensure that SMB 1.0/CIFS File Sharing Support is enabled if needed.
3. Local Security Policies: Since you mentioned checking the Local Security Policy, ensure that the settings regarding network access and sharing are consistent across all systems. Pay particular attention to settings related to guest access and authentication.
4. Service Startup Types: Verify that the necessary services for file sharing are set to Automatic on all systems. This includes services like Function Discovery Provider Host and Function Discovery Resource Publication.
5. Permissions: Double-check the NTFS and share permissions for the shared folder. Ensure that the permissions are set correctly for the user accounts or groups that are having issues.
6. Credential Manager: Since you've already added credentials via Credential Manager, ensure that there are no conflicting entries that might be causing the repeated prompts for credentials.
7. Firewall Settings: Check if there are any firewall settings that might be blocking access to the shared folder from specific systems. Ensure that file and printer sharing is allowed through the firewall.

If these steps do not resolve the issue, consider capturing network traffic to analyze the SMB requests and responses, which may provide further insights into the access problems.

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References:

• Can't access shared folders from File Explorer in Windows 10
• Access Denied when you access an SMB file share in Windows