Encountering the “Installation failed in the SAFE_OS phase with an error” message can be a frustrating roadblock when updating or installing Windows. This common yet perplexing issue often leaves users puzzled about what went wrong during the seemingly straightforward process. This guide is designed to demystify the error, offering clear, step-by-step solutions to troubleshoot and resolve the problem. 

What Is “Installation Failed in the SAFE_OS Phase with an Error”

To understand this issue, it’s crucial to grasp what the SAFE_OS phase entails in the Windows operating system’s installation or update sequence.

The SAFE_OS phase is a critical part of the Windows setup process, designed to prepare the system for the installation of a new version or update. It occurs before the system applies the new image, ensuring that all necessary conditions are met for a successful update or installation. This phase involves checking for compatibility, preparing the system files, and ensuring that the environment is secure for the update process.

The failure in the SAFE_OS phase can result from several underlying issues, making it a complex problem to diagnose and solve. Common reasons why the installation fails during this phase include:

  • System incompatibility: If the hardware or software of the system is not compatible with the new Windows update or version, the installation process might halt during the SAFE_OS phase. Microsoft regularly updates its system requirements, and it’s possible for older devices to fall out of compliance.
  • Corrupted system files: Corrupted or missing system files can prevent the installation from proceeding. These files are crucial for the operating system to run and update correctly.

Also read: How to Find and Fix Corrupted Files in Windows 10?

  • Insufficient disk space: Adequate storage is required for the installation files and the update process. If the system runs out of space, it can halt the update during the SAFE_OS phase.

Also read: How to Get More Disk Space on a PC or Laptop

  • Malfunctioning drivers or firmware: Outdated or corrupt drivers and firmware can cause compatibility issues, leading to failures in the SAFE_OS phase. These components are essential for the hardware and operating system to communicate effectively.
  • Interference from security software: Sometimes, antivirus or other security software can mistakenly identify the update process as a threat, interrupting the installation.

Understanding these potential reasons is the first step towards troubleshooting the “Installation failed in the SAFE_OS phase with an error” message. 

How to Fix “Installation Failed in the SAFE_OS Phase with an Error”

When addressing “Installation failed in the SAFE_OS phase with an error” during a Windows update or upgrade, several common solutions can effectively resolve the issue. Below are detailed steps for each method:

1. Run Windows Update Troubleshooter

Windows Update Troubleshooter is designed to detect and automatically fix issues related to Windows updates.

  • Go to Settings > Update & Security > Troubleshoot.
Update and Security
  • Select Windows Update and then click Run the troubleshooter.
  • Follow the on-screen instructions to complete the process.

After the troubleshooter completes, it will display any issues found and the fixes applied. Follow any additional instructions provided to resolve the detected problems.

2. Check and repair disk errors

Disk errors can prevent Windows from updating or installing correctly. The Check Disk utility (chkdsk) can locate and fix these issues.

  • Open Command Prompt as an administrator.
Run Command Prompt As Admin
  • Type chkdsk /f /r and press Enter. You may be prompted to schedule the scan at the next restart if the disk is in use.
Command Prompt chkdsk
  • Restart your computer if necessary to allow Check Disk to run and repair errors.

Alternative method:

Use the Disk Cleanup tool to remove temporary files and system files that might be causing issues.

3. Update drivers and BIOS

Outdated or corrupt drivers and BIOS/UEFI firmware can cause installation failures. Updating ensures compatibility and the smooth functioning of hardware during the update process.

If you are not familiar with the process of updating drivers manually, you can use specialized software like Auslogics Driver Updater to get things done in just a few clicks.
Auslogics Driver Updater

Also read: [EASY GUIDE] How to Update Device Drivers on a Windows 10 PC?

4. Disable security software temporarily

Security software can sometimes interfere with Windows updates or installations. Temporarily disabling your antivirus or security software can sometimes resolve the issue.

Here are the steps to take:

  • Press Win + I to open Settings, then navigate to Update & Security > Windows Security.
Windows Security
  • Click on Virus & threat protection. This will open the Windows Security window.
  • Under the Virus & threat protection settings, click on Manage settings.
Virus and threat protection manage settings
  • Toggle off Real-time protection. You may need to confirm your action or provide administrator permission.

Remember to re-enable your security software immediately after the update or installation process is complete to keep your system protected.

5. Perform a clean boot

A clean boot starts Windows with a minimal set of drivers and startup programs, helping identify if background programs are interfering with the update.

Here are the steps:

  • Type msconfig in the Start search box and press Enter.
Type in msconfig in Settings
  • In the System Configuration window, select Selective startup and uncheck Load startup items.
System configuration selective startup
  • Go to the Services tab, check Hide all Microsoft services, and then click Disable all.
  • Click OK, and restart your computer.

Reverting to normal startup:

Follow the same steps but choose Normal startup in the System Configuration window.

6. Use the Media Creation Tool for upgrade

The Media Creation Tool can help perform an upgrade or reinstall Windows while keeping files and applications intact.

  • Download the Media Creation Tool from the official Microsoft website.
Windows Media Creation Tool
  • Run the tool and select Upgrade this PC

Further Steps for a Successful Windows Installation

Preparing your system for a Windows installation or a significant update is a critical step that can save you from potential data loss and ensure a smooth upgrade process. Proper preparation involves a few key practices centered around data safety and system recovery options.

Backing up important data

Before initiating any fixes or reinstalling your operating system, backing up your important files and data is paramount. Data loss can occur due to various unforeseen complications during the installation process, such as system crashes or installation errors. Utilize external hard drives, cloud storage services, or USB flash drives to store your important documents, photos, videos, and application data.

Consider using Windows’ built-in backup feature. This tool is accessible via Settings > Update & Security > Backup.

Creating recovery media and a system restore point

Another crucial preparatory step is creating recovery media and a system restore point. Recovery media, which can be a USB drive or a DVD, allows you to boot your system and access repair tools if your computer fails to start after the update or installation. You can create recovery media through the Windows recovery environment by searching for “Create a recovery drive” in the start menu.

To create a system restore point, type “Create a restore point” in the Windows search bar, open the System Properties dialog, and follow the prompts under the System Protection tab.

Create a Restore Point on Windows 10


Tackling “Installation failed in the SAFE_OS phase with an error” requires careful preparation and systematic troubleshooting. By employing strategies such as utilizing Windows Update Troubleshooter, ensuring system compatibility, backing up essential data, and creating recovery media, you can navigate through this issue more effectively.


Pausing the update process is not recommended as it can cause further complications. If the update appears stuck, it’s best to check your internet connection and give it some time. Sometimes, updates may take longer than expected due to large files or slow internet speeds. If it remains stuck for an extended period, a system restart might be necessary, but this should be considered a last resort.
If you encounter the SAFE_OS error during a feature update, consider using the Windows 10 Media Creation Tool to perform an in-place upgrade. This method can help bypass the error by reinstalling Windows while keeping your files and applications intact. Always back up important data before proceeding with an in-place upgrade.
To minimize the chances of encountering the SAFE_OS phase error in future updates, regularly perform system maintenance tasks such as updating drivers, running disk cleanup, and keeping your antivirus software up to date. Additionally, before initiating an update, ensure your system meets the required specifications and that there is ample disk space available.
While it’s generally safe to delete temporary files and data from the Recycle Bin, manually deleting system files or folders can be risky and may harm your system. Instead, use the built-in Disk Cleanup tool, which safely removes unnecessary files, or consider moving large personal files (like photos, videos, and documents) to an external drive or cloud storage.