Fixing Windows Update Client Failed to Detect with Error 0xc8000643
The superb genius behind the Windows Update distribution made possible by Windows Server Update Service is unfortunately – occasionally – disrupted by a handful of irritating errors.
Basically, WSUS works by downloading Windows Updates from Microsoft, and making them available to all suitable Windows PCs across a local area network, where all PCs have a connection to the server hosting WSUS.
Despite the beauty of this arrangement, issues do occur with it from time to time. One of these is the “Client failed to detect” error, which displays the code 0xc8000643. Briefly explained, this fault is usually related to a client PC’s inability to find a Windows Update for which it has already been given access.
Below are some fixes that have been known to resolve this error.
Fix 1 – Stopping and Starting
Stopping and starting Windows services is the new “turn it off and back on again” – it is a great way to interrupt services that are running incorrectly, and usually it takes away the pressure of rebooting a business-critical server.
To stop the Windows Update service, go to Start > Run and enter C:\Windows\System32\Net stop WuAuServ
This will stop the Windows Update service. You should now wait a few moments, before proceeding.
Next, reinstall the Windows Update Agent. This can prove difficult, as it already exists on your system. To get around this, use one of the following links, depending on your server architecture:
- For x86-based computers (WindowsUpdateAgent20-x86.exe)
- For x64-based computers (WindowsUpdateAgent20-x64.exe)
Once downloaded, install the Windows Update Agent – you may find that Windows displays the following dialogue box as a response:
“Install is not needed since windows update agent is already installed.”
In this case, right-click the downloaded .exe file, go to Properties and in the file name box amend the file name so it reads:
You should then be able to proceed with installation.
Finally, after installation has completed, go to Start > Run and enter C:\Windows\System32\Net start WuAuServ to restart the service.
Fix 2 - Deleting Windows Update Temporary Folder
Another way to resolve this problem is by deleting the Windows Update temporary folder. This features some similar steps to the previous fix, and requires you to stop and start the Windows Updates service.
To stop the Windows Updates service, go to Start and enter services.msc in the Search box (or go to Manage my Server from the Start menu).
Under Services, find the Windows Update Service, and right-click – select Stop from the context menu.
This is a good opportunity to rename the SoftwareDistribution folder. You can find this by pasting %windir%\SoftwareDistribution\ into Start > Search.
In Windows Explorer, right-click the SoftwareDistribution folder and rename to SoftwareDistributionOLD.
Finally, return to Services and Start the Windows Update Service.
Future attempts to download and install updates should now be successful.