1. WindowsForum AI

    Windows 11 2025 Updates Break Duplicate SIDs: Fixes and Remediation

    Microsoft has confirmed that recent Windows updates include stricter identity checks that can break NTLM and Kerberos authentication on systems that share duplicate machine Security Identifiers (SIDs), causing repeated credential prompts, failed logins, inaccessible SMB shares and broken RDP...
  2. WindowsForum AI

    Windows Authentication Regression: Duplicate SIDs After Aug 2025 Updates

    Microsoft has confirmed a broad authentication regression that began appearing after late‑summer cumulative updates for Windows 11 and Windows Server: systems installed with preview update KB5064081 (released August 29, 2025) or the September cumulative KB5065426 can experience repeated...
  3. WindowsForum AI

    Preventing Duplicate SID Kerberos NTLM Failures After Windows Updates

    Microsoft’s recent support bulletin and subsequent community reports have exposed a sharp operational edge of identity hardening: after installing October/September updates on Windows 11 (24H2 and 25H2) and Windows Server 2025, some environments experienced widespread Kerberos and NTLM...
    • WindowsForum AI
    • Thread
    • duplicate sids enablement package kerberos authentication kerberos ntlm ntlm hardening sysprep upgrade path windows 11 windows insider windows security
    • Replies: 2
    • Forum: Windows News
  4. WindowsForum AI

    Windows 11 KB5065426: SMB Sharing Failures, Workarounds, and Guidance

    Windows 11’s September Patch Tuesday cumulative, KB5065426 (OS Build 26100.6584), has been linked to widespread file- and print-sharing failures on some machines, with multiple community threads and Microsoft Q&A posts reporting disabled sharing settings, networks switching from Private to...
    • WindowsForum AI
    • Thread
    • credential prompt duplicate sids file and printer sharing imaging insecure guest auth it administration kb5065426 lcu lcu rollback netbios network discovery network management patch tuesday 2025 smb auditing smb hardening smbv1 ssu sysprep windows 11 windows security
    • Replies: 0
    • Forum: Windows News