Microsoft's September 2024 Patch Tuesday update KB5046633 for Windows 11 has caused unexpected confusion among users, with reports of installation errors, performance issues, and unclear error messages. This cumulative update, intended to deliver security fixes and system improvements, has instead generated numerous support threads across Microsoft's forums and tech communities.

What KB5046633 Was Supposed to Deliver

The KB5046633 update included:
- Critical security patches addressing 45 vulnerabilities (5 rated Critical)
- Performance improvements for SSD storage systems
- Fixes for Bluetooth connectivity issues with certain peripherals
- Resolution for a memory leak in Windows Explorer
- Updated time zone information

The Problems Users Are Reporting

Multiple issues have surfaced since the update's release:

1. Installation Failures

Many users report seeing error messages including:
- "0x800f0922" (most common)
- "0x80070002"
- "We couldn't complete the updates, Undoing changes"

2. Post-Installation Issues

Even when successfully installed, some users experience:
- Increased CPU usage (particularly from "MsMpEng.exe" - Windows Defender)
- Start menu and search functionality becoming unresponsive
- Unexpected system reboots

3. Confusing Error Messages

The vague nature of Windows Update error messages leaves many users uncertain whether:
- The update failed completely
- Parts installed successfully
- Their system is now vulnerable

Microsoft's Response

As of September 12, 2024, Microsoft has:
- Acknowledged the installation issues in a support document
- Not officially pulled the update
- Suggested standard troubleshooting steps (see below)
- Not indicated when a revised update might be released

What Windows 11 Users Should Do

If You Haven't Installed KB5046633 Yet

  1. Delay installation if possible (use the "Pause updates" feature)
  2. Create a system restore point before attempting installation
  3. Ensure you have minimum 10GB free disk space

If You're Experiencing Installation Errors

  1. Run the Windows Update Troubleshooter (Settings > Update & Security > Troubleshoot)
  2. Reset Windows Update components:
    - Open Command Prompt as Admin
    - Run: net stop wuauserv
    - Run: net stop bits
    - Run: net stop cryptsvc
    - Rename C:\Windows\SoftwareDistribution to SoftwareDistribution.old
    - Run: net start wuauserv
    - Run: net start bits
    - Run: net start cryptsvc
  3. Try manual installation via the Microsoft Update Catalog

If You're Experiencing Post-Installation Issues

  1. Check for updated drivers, especially for:
    - Graphics cards
    - Storage controllers
    - Bluetooth/WiFi adapters
  2. Run DISM and SFC scans:
    - DISM /Online /Cleanup-Image /RestoreHealth
    - sfc /scannow
  3. Consider uninstalling the update if problems persist:
    - Settings > Update & Security > View update history > Uninstall updates

Why This Update Is Particularly Problematic

This situation highlights several ongoing challenges with Windows updates:

  1. Testing Limitations: Microsoft's reduced in-house testing since shifting to "Windows as a Service"
  2. Hardware Diversity: The vast array of PC configurations makes universal compatibility difficult
  3. Security Urgency: The need to push critical patches quickly sometimes overrides stability concerns
  4. Communication Gaps: Microsoft often doesn't clearly communicate known issues upfront

Enterprise Implications

For business users:
- WSUS and Windows Update for Business administrators should review update approvals
- Test the update on non-critical systems first
- Consider delaying deployment until Microsoft releases a revised update
- Monitor for increased help desk tickets related to update issues

Looking Ahead

While Microsoft hasn't announced a specific timeline, history suggests:
- A revised update (potentially KB5046635) may release within 2-3 weeks
- The company may quietly add known issues to the original update documentation
- Some fixes might be rolled into October's Patch Tuesday updates

User Workarounds

For those needing specific fixes from KB5046633:
- Security updates: Many can be installed individually via the Microsoft Security Update Guide
- Time zone updates: Can be manually imported
- Driver updates: Often available directly from hardware manufacturers

Final Recommendations

  1. Don't panic - Most systems without update errors are running fine
  2. Document your issues - Note error codes and symptoms for troubleshooting
  3. Check official sources - Microsoft's support site and @WindowsUpdate on Twitter
  4. Consider your risk profile - Security-critical systems may need to push through despite issues
  5. Wait for resolution - Microsoft typically addresses widespread update problems within weeks

This situation serves as a reminder that even routine Patch Tuesday updates can cause disruptions. Maintaining current backups and understanding update management options remains essential for all Windows 11 users.