How to fix "the installation failed in the SAFE_OS phase" during Windows 11 installation? This article will show you 5 methods to solve it effectively.
Want to upgrade or install Windows 11, but troubled by the error: the installation failed in the SAFE_OS phase? In this comprehensive guide, I will unpack what installation failed in SAFE_OS phase in Windows 11 actually means, why it happens, and most importantly, how to fix it step by step. I'll also cover a fast recovery option in case your system becomes unbootable during the process.
To understand the error, it helps to know how Windows installs major updates. The Windows 11 installation process happens in multiple phases, each with a specific purpose. The SAFE_OS phase is one of the earliest and most critical stages. During this phase, Windows boots into a temporary, minimal operating environment - similar to Windows PE.
In SAFE_OS, Windows prepares system files, checks hardware compatibility, installs low-level drivers, and configures essential security components such as Secure Boot and TPM. When the Windows 11 installation failed in the SAFE_OS phase occurs, it means Windows was unable to complete these early checks or preparations. Because this phase happens before the full operating system loads, even small issues can cause the installation to stop entirely. The error messages may vary:
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Although these messages look alarming, the underlying causes are usually practical and fixable:
Now that we know what's happening, let's move on to solutions for the installation failed in the SAFE_OS phase error. Before that, please temporarily disable third-party antivirus on computer and disconnect all your peripherals to prevent occasional clashes with Windows Update.
The Windows Update troubleshooter is designed to automatically detect and fix common update-related issues. While it may seem basic, it often resolves hidden configuration problems that cause SAFE_OS failures during Windows update.
Step 1. Press Windows + I to open Settings.
Step 2. Go to System > Troubleshoot > Other troubleshooters.
Step 3. Locate Windows Update and choose Run.
If update files or services are corrupted, Windows may fail during 0x800f0830 0x20003 SAFE_OS install_updates. Resetting Windows Update components forces the system to rebuild the update infrastructure from scratch.
Step 1. Press Windows + S, type cmd. And run Command Prompt as an administrator.
Step 2. Enter the following commands one by one, pressing Enter after each:
Step 3. Rename the update cache folders:
Step 4. Restart the services:
Step 5. Restart your PC and attempt the Windows 11 installation again.
Corrupted system files can interfere with Windows setup, especially during early installation phases. DISM and SFC scans repair these issues using built-in Windows tools. These scans repair core Windows components that SAFE_OS depends on. In many cases, this resolves persistent installation failed errors related to 0xc1900101 0x20017 SAFE_OS.
Step 1. Launch Command Prompt with administrator privileges.
Step 2. Run the DISM command:
Step 3. Wait for the process to complete. Then run the System File Checker:
Step 4. Restart the system after both scans finish.
Windows 11 has strict hardware and firmware requirements. If BIOS or UEFI settings are misconfigured, the installer may fail during SAFE_OS when checking security features. To reset and verify BIOS/UEFI settings:
Step 1. Restart the computer and enter BIOS/UEFI by pressing F2, DEL, or ESC during startup.
Step 2. Look for an option like Load Optimized Defaults or Default Settings.
Step 3. Ensure Secure Boot is enabled. And verify that TPM 2.0 is enabled and detected.
Step 4. Save changes and exit BIOS/UEFI.
When upgrades repeatedly fail, a clean installation may be the most reliable solution to get rid of 0x800f0830 0x20003 on Windows 11. This method bypasses upgrade conflicts by installing Windows 11 from scratch. But before proceeding, it is advised to back up all important data, as the process will erase all your personal files and settings. Then:
Step 1. Create Windows 11 installation media using Microsoft's Media Creation Tool.
Step 2. Boot the system from the installation USB.
Step 3. Choose Custom: Install Windows only.
Step 4. Select the target drive and proceed with installation.
Step 5. Complete setup and install drivers afterward.
Except for data loss during a Windows clean install, sometimes troubleshooting or failed installations may leave the system unstable or unable to boot. Thus, data backup is always crucial. AOMEI Backupper Standard provides comprehensive backup and recovery capabilities designed for Windows PCs. Below are some outstanding advantages of it:
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👉 Create backup: You can go to Backup, click File Backup or System Backup, select a storage path, and click Start Backup to create a backup image.
👉 Quick Restore: When needed, just run AOMEI Backupper, go to Home > Restore, then select the backup task or image for recovery easily.
For system restore, you are able to restore system image created on another working computer with different hardware with its Universal Restore (available in Pro version).
AOMEI Backupper also offers a Recovery Environment function that allows you to add a dedicated recovery boot entry to the system startup menu to load the WinPE recovery environment for restore operations (available in Pro version).
That’s all about how to resolve installation failed in the SAFE_OSphase on Windows 11. For data security, it's always recommended to backup important files or create system backup to an external hard drive before any major changes on computer, like system update. AOMEI Backupper Standard is simple to use and works for all Windows PCs. Try it for data protection now!