How to Fix Error Code 0x800b0100 on Windows 10?

by Jake Doe - -


Issue: How to Fix Error Code 0x800b0100 on Windows 10?

Hello. I could not install Windows Updates due to the error 0x800b0100 for quite a while. After some time, the error was resolved automatically and I managed to install the all available updates. The problem is that after the installation of updates, I cannot run a scan with Windows Defender due to the same 0x800b0100 error code. Is there something I could do or should I wait for the bug to be resolved automatically? Would highly appreciate your help!

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Solved Answer


Initially, the Error Code 0x800b0100 was referred to as Windows Update error. That’s because the only place it tended to appear was Windows Update service. The bug would prevent the ‘Check for Updates’ process and not allow the PC user to install any updates. In this case, specialists recommend restarting Windows Update services or disabling Proxy service temporarily. Unfortunately, but these days the error 0x800b0100 appeared under different circumstances. Quite a few Windows 10 users reported that this bug cases Windows Defender staying idle all the time. The icon of Defender keeps gray and the program is prevented from turning on. Whenever the PC user is trying to turn it on, the error message 0x800b0100 shows up saying:

An error has occurred in the program during initialization. If this problem continues, please contact your system administrator.
Error code: 0x800b0100

In this case, we would strongly recommend you to check the system for malware. That’s because malicious software may be blocking Windows Defender to prevent recognition and deletion. Thus, run a full system scan with Reimage and let it do the trick. We recommend this particular tool due to the fact that it’s a powerful PC optimization utility, which has a built-in Avira Antivir engine, so by using it, you will kill two birds with one stone.

How to Fix Error Code 0x800b0100 on Windows 10?

Method 1. Restart Windows Update components

If you are dealing with the 0x800b0100 error while installing Windows Updates, you should try to restart Windows Update components. However, resetting Windows Update Components requires the modification of some Windows Registry entries. Therefore, it’s advisable to make registry backups.

  1. Right-click Win key and select Command Prompt (Admin).
  2. If a UAC shows up, click OK to proceed.
  3. By typing the following commands you will stop BITS, Windows Update, Cryptographic, MSI Installer services. Don’t forget to press Enter after each of them:
    net stop bits
    net stop wuauserv
    net stop appidsvc
    net stop cryptsvc
  4. Then type Del “%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\qmgr*.dat” command to delete qmgr*.dat files.
  5. Once done, copy and paste cd /d %windir%\system32 command and press Enter to execute the command.
  6. To re-register BITS and Windows Update files, you will have to type all the commands (followed by Enter) provided below:
    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
  7. To reset Winsock, type netsh winsock reset and netsh winhttp reset proxy commands. Press Enter after each of them as usually.
  8. Finally, restart BITS, Windows Update, Cryptographic, MSI Installer services by entering the following commands each followed by Enter:
    net start bits
    net start wuauserv
    net start appidsvc
    net start cryptsvc

Method 2. Run sfc / scannow and DISM tools

To check and fix corrupted system files, you should perform the following steps:

  1. Click Windows key + X and select Command Prompt (Admin).
  2. Type sfc /scannow command and press Enter.
  3. Then type the following commands and hit Enter after each of them:
    DISM.exe /Online /Cleanup-image /Scanhealth
    DISM.exe /Online /Cleanup-image /Restorehealth
  4. Close Command Prompt and reboot the system.

Method 3. Perform a clean boot

If the culprit of the 0x800b0100 error when starting up Windows Defender is related to the third-party software, the best way to isolate the problematic software is to perform a clean boot. For this purpose, you have to:

  1. Press Windows key + R, type msconfig, and press Enter.
  2. Open Services tab and check the Hide All Microsoft Services box.
  3. Select Disable all and then open Startup tab.
  4. Select Task Manager and disable all processes on it. For this purpose, right-click on each of them and select Disable.
  5. Then press OK and reboot your PC.

If this method helped to fix 0x800b0100 error, enable third-party apps one by one and check which one causes Windows Defender’s malfunction. Once you find out the reason of the bug, enable other processes. For this purpose, perform the steps indicated above except that you have to uncheck Hide all Microsoft Services box on the Services tab.

Method 4: Set Windows Defender to start automatically

  1. Press Windows key + R, type services.msc, and press Enter.
  2. Find Windows Defender and double click on its service.
  3. Open Startup Type and set it to Automatic.

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