With cumulative Update, KB5003646 Microsoft released Windows 10 build 17763.1999 for devices running October 2018 update (Version 1809). This is an important update for Windows 10 1809 that brings both security and non-security fixes. All genuine devices connected to Microsoft server get install the update automatically via windows update. But some users report windows 10 update failed to install: 2021-06 Cumulative Update for Windows 10 Version 1809 for x64-based Systems (KB5003646) – Error 0x80070bc2 or 0x800f0984 .
Windows 10 update failed to install
The Windows 10 Update error 0x80070bc2 occurred when trying to install the Cumulative Update KB5003646 In fact, Windows 10 (version 1809) after downloading the KB5003646 update starts the installation, but at the end, the update installation is interrupted with error 0x80070BC2. for some other users installation gets to 70%, then it goes back to downloading. This has been happening over and over all day.
Fix Windows 10 KB5003646 failed to install
There are various reasons (security software, antivirus, buggy update, Corrupted update database cache) cause windows update stuck or failed to install etc. Here is the solution that worked for Me!
- In the search box on the taskbar, type cmd.
- Right-click Command Prompt in the search results and select Run as administrator. (Select Yes, when prompted by the User Account Control.)
- In the Administrator: Command Prompt window, type the following command and press Enter: SC config trustedinstaller start=auto
- Restart the PC.
In some cases, a second restart may be required. If you look under Settings > Update & security and you see the message Status: Awaiting restart, restart the PC a second time to complete the installation.
Clear update Database cache
If Windows 10 update KB5003646 stuck during download at 0% or 99% or completely failed to install, it might be that something went wrong with the file itself. Clearing the folder where all of the update files are stored will force Windows Update to download fresh files.
- To do this Type services.msc on start menu search and hit the enter key.
- Then look for windows update service, right-click on it and select stop.
- Do the same with its related service BITS ( Background Intelligent Transfer Service )
- Now Go to the following location.
- Delete everything in the folder, but do not delete the folder itself.
- To do so, press CTRL + A to select everything and then press Delete to remove the files.
Again open windows services and restart the services ( windows update, BITS ) which you previously stopped.
Run Windows Update Troubleshooter
After clear old, buggy update files, Run the windows update troubleshooter. This tool is specially designed to detect and fix problems prevents windows update to download and install.
- Press Windows + I to open the Settings app,
- Click on Update & security than Troubleshoot,
- Select Windows Update and click Run the troubleshooter,
- This will start to detect and diagnose the problems that prevent windows update to install.
- During the diagnose process this will check update service and its services running,
- Check update database for any corruption,
- Restart windows after complete the diagnostic process.
- And again check for windows updates from settings, update & security,
- Check if this helps to download and install Updates without any error.
Disable Security software & perform a clean boot
Also, Disable Any security software or antivirus protection ( if installed ), search for updates, install the available updates and then turn on your antivirus protection.
Clean booting your computer may also help. If any third party software causing confliction to download & install windows updates. Here’s how to do this:
- Go to the search box > type msconfig
- Select System Configuration > go to Services tab
- Select Hide all Microsoft services > Disable all
Hide all Microsoft services Go to Startup tab > Open Task Manager > Disable all the unnecessary services running there. Restart your computer and check for updates, hope this time windows updates download and install without any error.
Install Windows Update manually
If all the above solutions fail to fix the problem, still windows update stuck downloading or fails to install then let’s install windows updates manually. Visit the Windows 10 update history webpage where you can notice the logs of all the previous Windows updates that have been released.
For the most recently released update, note down the KB number.
Now use the Windows Update Catalog Website to search for the update specified by the KB number you noted down. Download the update depending on if your machine is 32-bit = x86 or 64-bit=x64.
(As of 10 June 2021 – KB5003646 (OS Build 17763.1999) is the latest patch for Windows 10 October 2018 Update. And KB5003635 (OS Build 18363.1621) is the latest patch for the windows 10 version 1909
Open the downloaded file in order to install the update.
That’s all after installing the updates simply restart the computer to apply the changes. Also If you are getting Windows Update stuck while upgrade process simply use the official media creation tool to upgrade windows 10 version 2004 without any error or problem.
Run DISM command
Sometimes fail to install update problems could be caused by corrupt system files. In this case, Microsoft suggests you run the DISM (Deployment Image & Servicing Management) tool to help you fix some Windows corruption errors. After that run command sfc /scannow and ok to scan and restore missing corrupted system files. after 100% complete the scanning process restart windows and check for updates.
Did any of these solutions help you fix the problem? Let us know in the comments below. Also, Read