The most common cause is a full or incorrectly set up System Reserved partition. Other possible reasons include VPN problems, outdated drivers, or conflicts with antivirus software. Now that you know the causes, let’s discuss the solutions.
1. Use the Latest Update Assistant to Update Your System
Typically, the 21H1 update should install automatically through Windows Update. However, if automatic installation fails, using the Update Assistant to manually install the update is often effective.
2. Perform DISM and SFC Scans on Your System
Corrupted system files can prevent updates from being installed successfully. Running DISM (Deployment Imaging Service and Management Tool) and SFC (System File Checker) scans will attempt to repair these files, potentially resolving installation failures.
3. Update Your PC’s BIOS to the Latest Version
An outdated BIOS can conflict with new Windows updates and prevent installation. Keeping your BIOS firmware up to date helps ensure compatibility with major Windows releases such as 21H1. Keeping your BIOS current ensures system stability and update compatibility.
4. Perform an In-Place Upgrade of Your PC’s Windows
If previous solutions have not resolved the issue, performing an In-Place Upgrade will reinstall Windows while preserving your settings, applications, and personal files. This process can resolve deeper system issues that prevent updates. If the issue persists, consider performing a repair installation of your current Windows setup. As a last resort, you may need to perform a clean installation of Windows 10. While this process is more involved, it is often the definitive solution for persistent update failures. By following the steps above, you can systematically address the most common reasons for Windows 10 21H1 update issues and restore your PC to full functionality.
