How to fix
Windows update error 0x800f0806
on Windows

Hello. Yesterday I tried to install an update on my Windows 11 laptop but it failed and I received a 0x800f0806 error. Is there any way to fix it?

Microsoft regularly releases updates to keep Windows running smoothly. Update packages can contain new features, bug fixes, and security patches.[ref en-1] Recently, a new update came out for Windows 11 - KB5017321. It is a mandatory security update that many users reported failing to install with the 0x800f0806 error.

Not installing security patches for your operating system can leave it vulnerable to attacks. Hackers can use vulnerabilities[ref en-2] to deliver their malicious programs. Keeping the update uninstalled is not an option when it comes to security patches. It is unknown why exactly the 0x800F0806 update error appears. However, there can be a few possibilities.

Most of the time, updates fail to install because of corrupted system files, and malfunctioning update components. It may also help to use the built-in update troubleshooter. In most cases, it can diagnose the problem and fix it automatically. When it does not, users have to take the matter into their own hands.

In this guide, you will find 6 steps that should help you fix Windows update error 0x800f0806. Unfortunately, manual troubleshooting can be a lengthy process. You can use a maintenance tool like [d1]. It can fix most system errors, BSODs,[ref en-3] corrupted files, and registry issues. Otherwise, follow the step-by-step instructions below.

Solution 1. Run Windows Update Troubleshooter

• Click the Windows button and select Settings
• Select System from the left pane, then scroll down on the right pane, and click on Troubleshoot
• Click on Other troubleshooters

• Locate the Windows Update troubleshooter and hit the Run button

Solution 2. Repair Corrupted System Files

Use Command Prompt commands to repair system file corruption:

• Open Command Prompt as administrator
• Use the following command and press Enter:
  sfc /scannow

• Reboot your system
• If SFC returned an error, then use the following command lines, pressing Enter after each:
  DISM /Online /Cleanup-Image /CheckHealth
  DISM /Online /Cleanup-Image /ScanHealth
  DISM /Online /Cleanup-Image /RestoreHealth

Solution 3. Delete Content from SoftwareDistribution Folder

• Click on the Start menu and type Services
• Find Windows update, Background intelligent transfer Service, and Cryptographic services
• Right-click on each of these, and select Stop
• Press the Windows key + l
• Select This PC from the Quick access sidebar
• Double click on (C:) drive
• Open Windows and find SoftwareDistribution/Download folder

• Select all the items there and Delete them
• Restart your computer
• Open Services again and select Start for each one

Solution 4. Install the Update Manually

If automatic download would not succeed, we recommend trying to download and install the update manually.

• Go to the official Microsoft Update Catalog website
• Type the KB number into the search bar, and press Enter or click Search

• You will find many different versions on the update – you need to find the one that matches your PC specs and Windows version (as a home user, ignore Windows server versions)
• After picking the correct version, click the Download button and proceed with on-screen instructions
• Restart your system once done

Solution 5. Reset Windows Update Components

• Open the Command Prompt as an Administrator
• Type the following commands one by one and press Enter after each:

  net stop bits

  net stop wuauserv

  net stop cryptsvc

  Del "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\qmgr*.dat"

  Ren %Systemroot%\SoftwareDistribution\DataStore DataStore.bak

  Ren %Systemroot%\SoftwareDistribution\Download Download.bak

  Ren %Systemroot%\System32\catroot2 catroot2.bak

  sc.exe sdset bits D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)(A;;CCLCSWLOCRRC;;;AU)(A;;CCLCSWRPWPDTLOCRRC;;;PU)

  sc.exe sdset wuauserv D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)(A;;CCLCSWLOCRRC;;;AU)(A;;CCLCSWRPWPDTLOCRRC;;;PU)

  cd /d %windir%\system32

  regsvr32.exe atl.dll

  regsvr32.exe urlmon.dll

  regsvr32.exe mshtml.dll

  regsvr32.exe shdocvw.dll

  regsvr32.exe browseui.dll

  regsvr32.exe jscript.dll

  regsvr32.exe vbscript.dll

  regsvr32.exe scrrun.dll

  regsvr32.exe msxml.dll

  regsvr32.exe msxml3.dll

  regsvr32.exe msxml6.dll

  regsvr32.exe actxprxy.dll

  regsvr32.exe softpub.dll

  regsvr32.exe wintrust.dll

  regsvr32.exe dssenh.dll

  regsvr32.exe rsaenh.dll

  regsvr32.exe gpkcsp.dll

  regsvr32.exe sccbase.dll

  regsvr32.exe slbcsp.dll

  regsvr32.exe cryptdlg.dll

  regsvr32.exe oleaut32.dll

  regsvr32.exe ole32.dll

  regsvr32.exe shell32.dll

  regsvr32.exe initpki.dll

  regsvr32.exe wuapi.dll

  regsvr32.exe wuaueng.dll

  regsvr32.exe wuaueng1.dll

  regsvr32.exe wucltui.dll

  regsvr32.exe wups.dll

  regsvr32.exe wups2.dll

  regsvr32.exe wuweb.dll

  regsvr32.exe qmgr.dll

  regsvr32.exe qmgrprxy.dll

  regsvr32.exe wucltux.dll

  regsvr32.exe muweb.dll

  regsvr32.exe wuwebv.dll

  netsh winsock reset

  net start bits

  net start wuauserv

  net start cryptsvc

• Wait for the process to finish and restart your PC

Solution 6. Repair Install Windows

• Visit the official Microsoft website to download Windows 11 Installation Media
• Run the Media Creation Tool and select Create Installation Media for another PC
• Select your USB drive
• Let the Process complete of writing the Installation files to the USB drive
• Click Finish
• On the PC you wish to upgrade, Press Windows + E to open the File Explorer
• Open the Removable drive and click Setup.exe
• Accept the license terms on the next screen

• Confirm the Upgrade options – Files, apps and Settings are kept
• Click Install, and the upgrade should start