I'm struggling with remote desktop protocol (RDP) and SMB access issues on my Windows 11 setup. I've spent an exhausting amount of time—a solid 45 hours—trying to resolve this without success. The error I keep encountering is: "Your credentials did not work. The logon attempt failed." I also face the same issue with Windows file sharing.
To give you some background, my setup involved cloning another Windows instance from a different CPU type (from Intel to AMD) and then performing a full recovery while retaining the settings and apps. I suspect there might be some underlying issues due to this cloning process. Also, I've encountered a related problem with MS Phone Link, which has always been a bit unreliable. Everything else seems to be functioning normally.
I'm really hoping to avoid a complete reinstall of Windows 11 and having to set up my development environment from scratch, as that would take forever.
Here's what I've already tried:
- Ensured my account isn't using PIN security.
- Cleared firewalls and checked all network settings, both on Wi-Fi and Ethernet.
- Attempted access using both local and Microsoft accounts.
- Verified network reachability through ping and share visibility.
- Double-checked that RDP and SMB are enabled on the server.
- Ensured local user accounts have valid passwords.
- Experimented with resetting Windows Firewall settings.
Despite all this, RDP and SMB connections fail with the same NTLM authentication error code 0xC000006D. I'd love to hear any suggestions on what could be causing this issue, especially since it appears isolated to this specific client machine. Could it be a broken credential provider, or something else altogether?
6 Answers
Don't forget to enable AES on the AD account you're using. There are checkbox settings for that, and it could potentially resolve your authentication issues.
In my experience, this seems to be a common NTLM issue. You could try enabling SMB1 on both machines and setting NTLM to the lowest settings to see if that allows a connection.
Clarifying the cloning process could help. Are we talking about cloning a VM or transferring a Windows install from one PC to another? Those processes can lead to different SID issues, especially if you're cloning bare metal.
I had a similar problem recently. Running the command 'ipconfig /release' followed by 'ipconfig /renew' fixed it for me. Might be worth a shot!
It sounds like you might be dealing with duplicate SIDs since you cloned your machine. This can definitely mess with authentication protocols like NTLM. You might want to check Microsoft's support page on this for a better understanding. Also, have you considered changing the hostname on your client machine? That might help too.
Make sure to check your LSA security packages on the cloned machine. You can find them in the registry at HKLMSYSTEMCurrentControlSetControlLsa. Make sure the defaults are in place, and consider comparing the SIDs of your machines to see if there are any mismatches.

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