Microsoft's latest Windows 11 KB5043145 update has brought both improvements and unexpected challenges for users. Released as part of the September 2024 Patch Tuesday, this mandatory security update includes critical fixes but has also triggered reboot loops on some systems, particularly those with BitLocker encryption enabled.

What's New in KB5043145

The KB5043145 update (OS Build 22621.4169) introduces several notable changes:

  • Microsoft Edge enhancements: Improved performance and security updates for the built-in browser
  • Taskbar improvements: Smoother animations and better multi-monitor support
  • File Explorer updates: Enhanced reliability when working with cloud files
  • Security patches: 23 critical vulnerabilities addressed, including remote code execution flaws

The Reboot Loop Issue

Numerous users have reported systems stuck in continuous reboot cycles after installing KB5043145. The problem appears most prevalent on:

  • Devices with BitLocker encryption enabled
  • Systems using certain third-party antivirus solutions
  • Computers with specific hardware configurations

Microsoft has acknowledged the issue in the Windows Health Dashboard, stating: "We are investigating reports of some devices experiencing restart loops after installing updates released September 10, 2024."

Temporary Workarounds

If you're experiencing reboot loops, try these solutions:

  1. Boot into Safe Mode:
    - Power cycle your PC three times to trigger Automatic Repair
    - Select Troubleshoot > Advanced Options > Startup Settings > Restart
    - Choose Safe Mode with Networking (F5)

  2. Uninstall the update:
    - In Safe Mode, open Command Prompt as admin
    - Run: wusa /uninstall /kb:5043145

  3. Disable BitLocker temporarily:
    - From recovery console: manage-bde -off C:

Microsoft's Response

The Windows team has been actively collecting diagnostic data through the Feedback Hub (category: "Install and Update" > "Downloading, installing, and configuring Windows Update"). Engineers are working on a resolution expected in the October 2024 cumulative update.

Should You Install KB5043145?

For most users, the security benefits outweigh the potential risks. However, consider delaying installation if:

  • Your device is mission-critical
  • You rely on BitLocker without recovery options
  • You've experienced similar issues with previous updates

Looking Ahead

Microsoft has stated that future updates will include better validation for BitLocker interactions. The company is also enhancing its Windows Insider program to catch similar issues before general release.

For the latest updates on this situation, monitor the official Windows Health Dashboard and Microsoft's support channels.