Software⏱️ 3 min read📅 2026-06-11

How to Fix: WINDOWS 10 - Error Windows Update 10 = Error in phase " SAFE_OS " with the operator error with " BOOT "

Windows Update error with SAFE_OS phase and BOOT operator

Quick Answer: Try reinstalling Windows 10 or checking for corrupted system files.

The error 'Windows Update: The installation failed in SAFE_OS phase with an error when BOOT operator' (code 0xC1900101 - 0x20017) is a common issue affecting Windows 10 users. This error occurs when the operating system fails to boot into Safe Mode, which is necessary for troubleshooting and resolving system issues.

It's frustrating because this error prevents users from updating their Windows 10 installation, leaving them vulnerable to security threats and outdated software. In this guide, we'll help you identify the root cause of this error and provide two effective methods to resolve it.

🛑 Root Causes of the Error

  • The primary reason for this error is a corrupted system file or registry key that prevents Windows from booting into Safe Mode. This can occur due to various reasons such as a failed Windows Update, software conflicts, or hardware issues.
  • Another possible cause of this error is the recent migration of your operating system using Paragon Migrate OS to SSD, which may have introduced compatibility issues with your system files and registry.

🛠️ Step-by-Step Verified Fixes

Reinstalling the Windows 10 Media Creation Tool

  1. Step 1: Download the latest version of the Windows 10 Media Creation Tool from Microsoft's official website.
  2. Step 2: Run the tool and select 'Create installation media' to download the ISO file for your Windows 10 installation.
  3. Step 3: Insert a USB drive with at least 8GB of free space into your computer and run the tool again. Select the USB drive as the installation media and follow the prompts to create the installation media.

Manually repairing system files using the Command Prompt

  1. Step 1: Open the Command Prompt as an administrator by searching for 'cmd' in the Start menu, right-clicking on it, and selecting 'Run as administrator'.

✨ Wrapping Up

To resolve the error 'Windows Update: The installation failed in SAFE_OS phase with an error when BOOT operator' (code 0xC1900101 - 0x20017), try reinstalling the Windows 10 Media Creation Tool or manually repairing system files using the Command Prompt. If these methods don't work, consider seeking further assistance from Microsoft support or a professional IT technician.

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