Error 0x80071AA8 – 0x2000A, installation failed in SAFE_OS phase


While upgrading from an older version of Windows OS to a higher version of Windows OS, like Windows 11 or Windows 10, or while installing updates, some users have encountered the 0x80071AA8 – 0x2000A, Failed to install in SAFE_OS phase Mistake. The full error message that appears on the screen while upgrading or updating Windows is:

Error 0x80071AA8 – 0x2000A, installation failed in SAFE_OS phase with error during PREPARE-SAFE-BOOT operation

If you receive this error when upgrading to a higher version of Windows, one of the possible causes for this problem is that you are installing the Windows operating system on a different hard drive, such as an SSD, but your user profile is on a different hard disk, for example a hard disk. Apart from this, there are also other causes that can trigger this error. In this article, we will see some solutions to fix the error “0x80071AA8 – 0x2000A, Failed to install in SAFE_OS phase” on the Windows computer.

What is the SAFE_OS phase?

When you turn on your computer, the firmware settings are first loaded and a disk system check is started. In the next step, the operating system is loaded by the Windows boot manager. After that, WinLoad.exe loads important drivers to start the kernel which loads registry settings and additional drivers and gives control to the system manager process. Now your user interface and the rest of the software are loaded and you see the login screen. The SAFE_OS phase is where the system verifies that everything, including the drivers, is working properly as expected. During this phase, if anything uncertain is found or any of the signatures are missing, the installation may fail in the SAFE_OS phase error.

Lily: Description of the Windows startup process

What is Operation PREPARE-FIRST-BOOT?

The First Boot operation allows a computer to load an operating system either from the internal hard drive or from the external hard drive or USB flash drive connected to it. Boot order can be changed in BIOS settings.

Error 0x80071AA8 – 0x2000A, installation failed in SAFE_OS phase

If you upgrade to a higher version of Windows and receive this error, Windows installation will be interrupted. In this case, revert to the previous version of Windows and try the following fixes. After that, upgrade Windows or run Windows update again.

Before proceeding, make sure your system meets the hardware requirements for the version of the Windows operating system you want to install. Also check if all your drivers are up to date.

  1. Run Windows Update Troubleshooter
  2. Reset Windows Update Components
  3. Temporarily disable your antivirus
  4. Update Windows Using Windows 10 Update Assistant
  5. Change your BIOS mode from Legacy to UEFI
  6. Create a new user account
  7. Clean Windows Installation

Let’s see all these solutions in detail.

1]Run Windows Update Troubleshooter

Windows Update Troubleshooter

Windows Update Troubleshooter is an automated tool developed by Microsoft that helps users troubleshoot issues with Windows updates. You can access this tool through your Windows 11/10 settings. Run the Windows Update troubleshooter and let it detect and fix issues. Once the troubleshooting process is complete, check if you can install the Windows update.

2]Update Windows using Windows Update Assistant

If your system is running Windows 11/10 and Windows 10 update fails due to this error, you can use Windows Update Assistant to install the latest Windows updates. Windows Update Assistant downloads and installs feature updates on a Windows device. You can download it from

3]Reset Windows Update Components

Windows Update components are the essential part of Windows update. If there is a problem with the Windows Update components, you will not be able to install the latest Windows updates and you may get several errors while updating your system. One way to fix Windows Update issues is to reset Windows Update components. After manually resetting Windows Update components to default, you should be able to install the latest Windows updates. If the problem persists, there may be another reason for the problem. Try the following solution.

4]Temporarily disable your antivirus

Sometimes antivirus software prevents Windows from installing the latest updates. This is definitely an antivirus false positive indicator. It is possible that your antivirus is interfering with the Windows update due to which you are getting this error message. One way to check this is to temporarily disable your antivirus. If this solves your problem, you can activate your antivirus after updating your system. If that doesn’t work, you should try other troubleshooting methods. Therefore, go ahead and try the next potential fix.

5]Change your BIOS mode from Legacy to UEFI

An effective solution to fix this issue is to enable UEFI mode in your system BIOS. For this, your BIOS must support UEFI mode. You can check your system’s BIOS mode in the System Information console. To launch it, click Windows Search and enter system information. After that select the System Information app from the search results.

System Information

If your BIOS mode is set to Legacy, change it to UEFI and check if that fixes the issue. To do this, your BIOS must support UEFI mode. To check this, enter your system BIOS and select the BIOS mode option. If it displays both Legacy and UEFI, your system supports both Legacy and UEFI BIOS modes. Now you can switch from Legacy mode to UEFI BIOS mode.

6]Create a new user account

If you have two hard drives installed in your system, let’s say one SSD for the Windows operating system and one hard drive for your user data. In this case, if your user profile is created on a hard disk other than the one where Windows is installed, your system will not be able to find the path of your user profile and you will get this error message. To resolve such a problem, edit a registry value and then create a temporary user account.

The step-by-step process is explained below.

press the Win + R keys to launch the Run command box. Now type regedit and click OK. Click Yes in the UAC prompt. This will open the Registry Editor.

When Registry Editor opens, navigate to the following path. To do this, copy the following path and paste it into the address bar of the registry editor. After that press Walk in.

HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindows NTCurrentVersionProfileList

Change the ProfilesDirectory value in the registry

Make sure the ProfileList key is selected on the left side. Right click on the ProfilesDirectory Value on the right side and click Edit. Type %SystemDrive%Users in Value data and click OK.

Close Registry Editor and create a temporary local administrator account. Restart your computer from the newly created user account to install updates.

Windows Updates should install this time without any errors. After installing updates, you can delete the temporary local administrator account.

7]Clean Windows Installation

If none of the above solutions fixed the error, a fresh installation of the Windows operating system will help. Note that a clean install will erase everything from the drive you are installing Windows to. Therefore, it is best to back up your data before performing a clean install.

I hope this helps you.

Read more: 0xC1900101 – 0x20017, Installation failed in SAFE_OS phase with error during BOOT operation.

Error 0x80071AA8 - 0x2000A, installation failed in SAFE_OS phase


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