0xC0000064 | No such user

Industry

Systems & Devices

Canonical

/systems/security-systems/error-codes/0xc0000064/

Last Updated

Feb 27, 2026

Summary

The specified user name does not exist or could not be found by the authentication system.

Learn More

Use these links to pivot between the directory, a focused guide, and nearby related codes.

Hub

Guides

Security System Error Codes: Sensors, Panels, Battery, and Communication Issues

Related Codes

What This Code Means

0xC0000064 is an NTSTATUS authentication result commonly observed in Windows security logs and authentication traces. It indicates the username provided could not be matched to an account in the authentication database (local SAM or directory service).

Where Users Usually See This Code

Windows Security event logs (failed logons)
RDP, SMB, or domain authentication attempts
SIEM alerts and authentication monitoring

Why This Code Appears

Username mistyped
Account was deleted/renamed
Wrong domain/realm used

What Typically Happens Next

Logon fails and access is denied

What This Code Is Not

It is not a password-correctness indicator
It is not proof of an intrusion by itself

Troubleshooting Checklist

□ Verify the username and domain/tenant context
□ Confirm the account exists and is enabled
□ Review the source host and protocol to determine whether this is user error or automated traffic

Notes And Edge Cases

Automated scans and misconfigured services can generate many “no such user” events.

Related Codes

8 links