Fix Error 0x800F0955 – 0x20003 while installing Windows 11

Recently, a few users encounter an error 0x800F0955 – 0x20003 when they were trying to reinstall Windows 11 on their devices. If you have also come across such an issue, read and apply the five fixes discussed in this post. In cases where no solution deems a possible fix, simply clean install Windows 11. 

Why Windows 11 is failing to install?

Windows 11 may fail to install on your computer when it doesn’t meet the minimum system requirements for it. Here’s a list of that –

• Processor – 1 GHz or faster with minimum 2 cores on a 64-bit processor or System on a Chip (SoC)
• System firmware – UEFI with Secure boot capable
• Storage – A minimum of 64 GB spaces
• RAM – At least 4 GB; recommended – 8 GB
• TPM – Version 2.0

Fix Windows 11 Reinstallation Error 0x800F0955 – 0x20003

As stated above, Error 0x800F0955 – 0x20003 mostly occurs when you are trying to reinstall on your computer. To fix this issue then, you may apply the below workarounds and see if any resolve this issue on your Windows 11 PC. The solutions are as follows –

• Check Network connectivity
• Troubleshoot Windows Update
• Rename Old Migration Files and Remove Developer Mode Package
• Run SFC and DISM Scans
• Lack of storage spaces 
• Use Windows Update Assistant or Media Creation Tool

Note: Before you attempt the solutions provided below, make sure to check the minimum system requirements to run Windows 11 OS on your PC. To view the complete list of all other system requirements, visit this webpage.

1] Check Network connectivity

Many a time, installation or upgrade errors on Windows 11 appear simply because of the low internet speed. Go and surf different sites on your default web browser and check if you face any difficulties there as well. 

To install Windows 11, it is optional to remain connected to an active internet connection. So, when you try reinstalling the new OS, you better disconnect your device from any active network. After you disconnect the access to the Internet to the ISO image, attempt again to reinstall Windows 11. 

After you complete the OOBE (Out-Of-Box Experience), turn back On the network connectivity. Reach out to the below path next and hit Check for updates.

Settings (Win + I) > Windows Update > Check for updates

2] Troubleshoot Windows Update

Troubleshooting Windows Update is another useful tool that you may start to find and resolve the error 0x800F0955 – 0x20003 on Windows 11. Here’s how to launch and start troubleshooting Windows update –

• First of all, launch Settings by pressing Win + I altogether. 
• Select System on the left navigation and then Troubleshoot on the right end. 
• Click Other troubleshooters, and hit the Run button besides Windows Update.
•  When the troubleshooter window opens up, click Next and follow the on-screen instructions. 

Even in cases where it doesn’t solve the underlying causes, this will let you know of a few working ways. All you have to do then is to follow the steps as provided in that fix. 

3] Rename Old Migration Files and Remove Developer Mode Package

As per some users, they fix the error 0x800F0955 – 0x20003 by removing the developer Mode Package and after then renaming the Old Migrations files. You may perform both these tasks on Command Prompt having administrative privileges –

• Press Win + R to invoke the Run dialog.
• Type CMD and hit Ctrl + Shift + Enter keys altogether.
• When the UAC window comes into the display, hit Yes to allow accessing CMD as Admin.
• On the elevated console, run these codes one by one –

dism /online /remove-package /packagename:Microsoft-OneCore-DeveloperMode-Desktop-Package~31bf3856ad364e35~amd64~~10.0.17134.1

• Now that you have removed the Developer Mode Package, rename the migration files by executing these two codes –

ren C:\Windows\System32\migration migration.old

ren C:\Windows\System32\migwiz migwiz.old

• Restart your PC next so that changes made become effective from the next logon.

4] Fix File Corruptions using SFC and DISM

Missing system files or damaged ones may also prevent Windows 11 from installing on your computer. You may confirm this by using tools like SFC and DISM. Here’s how to run both these tools simultaneously –

• Launch CMD as administrator first.
• On the elevated console, type the following, and press Enter –

DISM /Online /Cleanup-Image /RestoreHealth

• Wait while the above code runs successfully. Once this is over, execute this command next –

sfc /scannow

The SFC tool will diagnose all the system files, repair or re-generate them, thus fixing error 0x800F0955 – 0x20003 on Windows PC. 

5] Clear temporary files or old Windows installation(s) via Disk Cleanup

Lack of storage spaces may also trigger an error code 0x800F0955 – 0x20003 while installing Windows 11 OS. To fix this issue then, you may use the Disk Cleanup Tool and get rid of unnecessarily stored cache, temporary files, or old Windows installation(s). 

6] Use Windows Update Assistant or Media Creation Tool

If none of the above solutions work in your favor, it’s time to use the Windows Update Assistant tool or Media Creation Tool to get Windows 11 ISO file. Once you have the required Image disk, make it bootable, and use that to clean install Windows 11 on your computer.

I hope this tutorial helps you to overcome the error code 0x800F0955 – 0x20003 while installing or reinstalling Windows 11.