Three solutions to the error code 66A of update prompt in win10


When the win10 system is updating, the error code 66A appears, which causes the update failure. What is the cause of this problem? How to solve this problem? Next, we will introduce in detail the causes and solutions of error code 66A in update under win10 system. Please see the details below.

Software name:
Adwclean toolbar and ad clear v7.2.1.0 official English free installation version
Software size:
Update time:
Software name:
CCleaner Chinese Version (system cleaning tool) v5.59.7230 green single file enhanced version 64 bit
Software size:
Update time:

1、 Cause analysis:

–Malware or virus infection

–Windows registry corrupt

–Net framework software installation is damaged or incomplete.

At the same time, we compiled the appropriate solution to fix the windows update error code 66A. You can try any of the solutions listed below to solve the problem.

2、 Solutions

Solution 1: scan your PC for malware

Some windows users ignore the warning message and click the available link in the message that contains the malware. At the same time, the ideal next step is to use Malwarebytes adwcleaner to remove malware from your Windows PC. This program is a free utility that will scan and remove pups from your computer. The following is downloaded on a Windows PCHow to install and use malwarebytesadwcleaner:

–Download Malwarebytes adwcleaner on the official website.

–Double click to download the EXE file and follow the prompts to complete the installation.

–When the installation is complete, right-clickMalwarebytes adwclean Icon, and then select“Run as Administrator”To open the program.

–In the Malwarebytes adwcleaner display, click the scan button to start the scan operation.

–When the scan is complete, click“Clear “Button.

–Now, when prompted to restart your PC to finish cleaning, click OK.

Solution 12: run SFC scan

Or you can run a full system scan on a Windows PC with powerful antivirus programs,Such as BitDefender (world’s Nr.1), bullguard, avast and AVG to remove viruses and malware.

The system file checker scans for damaged or missing system files and repairs them. Here’s how to run SFC scan on a Windows 10 PC:

–Go to“Start > type CMD > right click command prompt > select run as administrator.

–Now, typeSFC / scannow command.

–Wait for the scan process to complete, and then restart the computer. All damaged files will be replaced on restart.

In addition, you can use special tools such as Ashampoo win optimizer and iolo System mechanism to check for system file corruption. However, if the error prompt still exists, you can proceed to the next method.

Solution 3:Using CCleaner

Software remaining, missing DLLs and invalid Windows registry keys may also cause windows update error code 66A problems. At the same time, you can use CCleaner to repair the windows registry and make it error free.

Here’s how to download, install, and use CCleaner:

–Download the free version of CCleaner or download the CCleaner Pro version.

–Install and follow the prompts to complete the installation.

–When the installation is complete, start CCleaner, and then click“Analysis “Options.

–After CCleaner has finished scanning, click“Run Cleaner”。 Follow the prompts to enable CCleaner to repair the windows registry.

The above are the three solutions to update error code 66A in win10. I hope you like it. Please continue to pay attention to developeppaer.

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