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Microsoft released on October 1, 2024 the Windows 11 24H2 update, also known as “Update 2024”, which will soon be available for download and installation on all computers running Windows 11 23H2 or 22H2 through Windows Update.
However, some users – including me- who already tried to upgrade their systems to Windows 11 version 24H2, reported that the 24H2 update fails to install with error:
“We couldn’t install Windows 11
We’ve set your PC back to the way it was right before you started installing Windows 11
0XC1900101 – 0x20017
The installation failed in the SAFE_OS phase with an error during BOOT operation”
After encountering the “0XC1900101 – 0x20017″ problem when trying to upgrade Windows 11 23H2 to 24H2 on two physical machines and one VirtualBox virtual machine, I came to the conclusion that the problem is due to the fact that the currently available release of Windows 11 24H2 (October 2024) has and is causing many problems during or after the installation and this is another reason why Microsoft does not recommend to upgrade yet.
Therefore, if you are unable to install Windows 11 24H2 update due to error “0XC1900101– 0x20017: Installation failed in SAFE_OS phase”, I suggest you do not update your system yet and wait until Microsoft releases a new version of Windows 11 24H2.
However, if you want to want to troubleshoot the Windows 11 24H2 “0XC1900101 – 0x20017″ update error, follow the instructions below.
How to FIX: 0XC1900101–0x20017 – Installation failed in the SAFE_OS phase, on Windows 11 24H2 update installation. *
* IMPORTANT: Before applying the methods mentioned below to troubleshoot the Windows 11 24H2 “0XC1900101–0x20017” upgrade problem, do the following:
- If you have BitLocker encryption enabled on your system, go ahead and suspend BitLocker before installing the update (very important) and re-enable BitLocker after the update is successfully installed.
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Make sure you have more than 64 GB of free space on your C: drive before you install the update.
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Disconnect all USB devices that are not needed for the update. (e.g. USB Drives, USB Flash Disks, USB Printer etc.)
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Download and install all available Windows updates.
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Disable -or better- temporarily uninstall all non-Microsoft security software (antivirus, antimalware, firewall, etc.), to avoid installation problems during the upgrade.
* Important note for users with unsupported hardware for Windows 11 24h2: Windows 11 24H2 has one more hardware requirement to install: The Processor must support the SSE4.2 instructions set, otherwise the system may not be able to boot or show the error “0XC1900101 – 0x20017”. Therefore, before you try to install Windows 11 v24H2 on the unsupported computer, make sure that its CPU supports SSE4.2 (Intel) or SSE4A (AMD) instructions, with CPU-z.
* Important note for VirtualBox users: If you encounter the mentioned issue after installing Windows 11 24H2 on a VirtualBox virtual machine, download & install the latest version of VirtualBox and then try again to upgrade the VM to Windows 11 version 24H2.
Method 1. Update Device Drivers.
Step 1. Install all Windows & Optional Updates.
1. Navigate to Start -> Settings -> Windows Update and click Check for updates to find and install all Windows updates.
2. Then, in Windows Update screen click Advanced Options and then click Optional Updates under “Additional Options”.
3. In Optional updates, check all the checkboxes to install all the available Windows and Driver updates and click Download & install.
Step 2. Download Latest Drivers from Manufacturer’s webpage.
1. Navigate to your device manufacturer’s support site and check if any new drivers are available for your device’s hardware. If so, download and install them.
Method 2. Upgrade to Windows 11 24H2 using the Installation Assistant.
Microsoft’s recommended method to resolve the mentioned issue is to upgrade your Windows 11 system to version 24H2 using the “Windows 11 installation assistant”. To do this:
1. Navigate to Windows 11 download site to download the Windows 11 Installation Assistant.
2. Then run the “Windows11InstallationAssistant.exe” and choose YES at the UAC warning
3. Accept the License Terms and then wait the Installation Assistant to download the required files and install the update.
4. When the process is complete, click Restart Now to complete the installation
5. After restart, the installation will continue and after a few minutes will end.
6. Finally, navigate to Windows Update and check if there are any other updates available to install. If so, let Windows to install them and you’re done!
Method 3. Update BIOS/FIRMARE.
An outdated BIOS can also cause the error “0XC1900101 – 0x20017″ in Windows update. So, try to update the BIOS and see if that fixes the problem. To update the BIOS on your device:
1. As soon as you turn ON the PC, press the DEL or F2, or F10 or F12 key to get into the BIOS/UEFI Firmware Settings.
* Note: The way to enter BIOS/UEFI settings varies from manufacturer to manufacturer. If you do not enter the BIOS settings using the above-mentioned keys, check the manufacturer’s instructions for your motherboard (desktop) or device (laptop).
2. Locate the BIOS version information within the BIOS settings. This information is usually found in the “Main” or “General” tab.
3. Then visit the computer or motherboard manufacturer’s support page and check if there is a more updated BIOS/FIRMWARE version than the one you have.
4. Finally, and if your BIOS/Firmware version is old, update the BIOS according to the manufacturer’s instructions.*
* Cautions:
1. The BIOS Update is the last solution to solve computer problems, because if you incorrectly update the BIOS, you ‘ll make your computer unbootable and useless. So, be very careful when updating your BIOS and do not power off your PC during the BIOS update process. If you’re not comfortable doing it yourself, it’s always best to consult a qualified technician to avoid any potential issues.
2. To avoid problems during and after BIOS update, do the following:
a. Backup your files to an external storage device. (e.g. To a a USB disk)
b. Turn off the BitLocker protection.
c. Disable TPM before updating BIOS to avoid Windows 11 activation problems after update.
d. After TPM is disabled, you may not be able to sign-in to Windows using your PIN or fingerprint. So make sure you remember your password so you can log in to Windows.
Method 4. Force Windows to Recreate the Windows Updates Store folder.
A common method to solve errors in Windows Update, is to force Windows to recreate the Windows Update Store folder (“C:WindowsSoftwareDistribution“), which is the location where Windows stores the downloaded updates. To do that:
1a. Press the Windows 
+ R keys to open the Run command box.
1b. In run command box, type “services.msc” and press Enter to open the Windows Services control panel.
2. Right-click on Windows Update service and select Stop.
3. Then, open Windows Explorer, navigate to C:Windows folder and open it to explore its contents.
4. Select and Delete the “SoftwareDistribution” folder. (Click Continue at “Folder Access Denied” window).
* Notes:
1. After deleting this folder, the next time the Windows Update will run, a new empty “SoftwareDistribution” folder will be automatically created by Windows to store updates.
2. If you cannot delete the folder because of error “Folder in use – try again”, then delete it after starting Windows in “Safe Mode”.
5. Restart your computer and then try to install updates.
Method 5. Fix Windows Update Error 0XC1900101–0x20017 by repairing system files.
The next method to fix the error 0XC1900101–0x20017 in Windows 11 24H2 update, is to repair the Windows installation and System Files using the DISM and SFC tools.
1. Open Command Prompt as Administrator. (To do that, type “cmd” in Search and then at “Command Prompt” result, select “Run as Administrator”)
2. At the command prompt window, type the following command & press Enter:
- dism.exe /Online /Cleanup-Image /Restorehealth
3. Be patient until ‘Deployment Image Servicing and Management’ (DISM) tool repairs the component store.
4. When the operation is completed, give the command below to repair the system files and press Enter:
- sfc /scannow
5. When SFC scan is completed, restart your computer.
6. After restarting try to install the Windows 11 24H2 update again.
Method 6. Upgrade to Windows 11 24H2 using Windows 11 ISO file.
Another method to solve the mentioned problem is to repair & upgrade Windows from a Windows ISO file. For this task, read the instructions in the following article:
Method 7. Clean Install Windows.
The final method to fix the mentioned problem, is to backup your files and to perform a fresh installation of Windows. For this task, read the instructions in the following article:
That’s it! Which method worked for you?
Let me know if this guide has helped you by leaving your comment about your experience. Please like and share this guide to help others.
