Windows Update Error Code 646 [SOLVED]

Windows update error codes are used to communicate errors encountered during installation of Windows Updates. These error codes help identify the cause of the failure and provide instructions for troubleshooting. You can use these error codes to determine what action needs to be taken to correct the problem.

Error Codes

The following table lists common error codes associated with Windows Update. For complete descriptions of each error code, refer to KB Article 959056.

Code Description 0x00000001 An unexpected error occurred while installing the update. 0x00000002 A critical update failed to install because it could not connect to the network.

0x00000003 An unknown error occurred while checking for updates. 0x00000004 An unknown error occurred while updating files. 0x00000005 An unknown error occurred during installation of the update. 0x80000001 The download server did not respond correctly.

0x80000002 The download server responded too slowly. 0x80000003 The download server timed out.

0x80000004 The download server returned an invalid response. 0x80000005 The download server reported an internal error.

Running the Windows Update Troubleshooter

If you are receiving the following error message while updating Windows 10:

The Windows Update Service failed to start because of the following error: 0x800704CD

You can use the Windows Update Troubleshotting Tool to diagnose and repair the problem.

To download and install the Windows Update Troubleshopping Tool, follow these steps:

Click here to go directly to the Windows Update Troubleshopting Tool web site.

Download the latest version of the tool.

Run the downloaded file.

Using the Windows Update Catalog to put in the update

The update KB972363 contains several changes related to Windows Defender Application Guard technology. These include improvements in performance, reliability, compatibility, and stability.

If you want to download and install the update, you can do so directly from the Windows Update Catalog. However, we recommend downloading the update from our servers because it allows us to test the update before releasing it to you.

You can use the Windows Update Catalog to download the update KB972363.

Then, under Optional Updates, click View optional updates.

In the list of optional updates, scroll down until you see the update KB972364. Click Install now to begin downloading the update.

When prompted, enter the product key for the software you wish to update.

After the update completes, restart your computer and enjoy the benefits of the updated application.

Start Windows Update and Background Intelligent Transfer against your will

To force starting Windows update and Background Intelligent Transfer services, go into the services window and find them under category called Microsoft Updates. Rightclick on each one and select Properties. Set Startup type to Automatic and set the Startup Type to Manual. Then restart the computer.

If you still encounter an error code 645 while installing a Windows update, follow these steps.

Force starting the Windows Update and the Background Intelligent Transfer Services.

When you encounter an error code 740 while attempting to install a Windows update on a PC running Windows 10 version 1809, check out these solutions.

#1 – Disable the Automatic Download of Updates

Click Turn On settings. Scroll down and uncheck Automatically check for updates. Close the dialog box. Restart the system.

#2 – Disable the Automatic Installation of Updates

Using Registry Editor to get rid of the AppData Key

Users who encounter the error code 0x646 often find that clearing theAppData folder resolves the issue. This fix works even if you’re unable to access theAppData folder because it’s located elsewhere. When performing this fix,make sure that you don’tdelete any other folders within theUserShellFolder. This issue occurs due toan incorrect entry inthe registry. A quick way toclear out your entireregistry is todownloadRegCurePro.To fix theissue,simply delete thekeyHKEY_CURRENT_USERSoftware\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders.

Turning off or removing a third-party firewall (if applicable)

The main reason why people use a third-party firewall is because it makes life easier. You don’t have to worry about installing drivers or updating programs anymore. However, there are some drawbacks to using a third-party firewall. In this article we’ll show how to disable and uninstall a third-party firewall, so you can install Windows Updates without interference.

If you’re running Windows 10, you probably already know what to do. For older versions of Windows, read on.

Using System Restore

System Restore is one of those tools that most people don’t know about, but it could save your day. If you’re having problems with Windows 10, or just want to make sure everything works properly, there are some things you can do to help fix issues without reinstalling. One of those is to use System Restore.

This feature allows you to roll back changes made to your computer. You can go back to a previous version of Windows, programs installed, files saved, etc. You can even go back to a specific date and time, or restore your PC to a state where it worked perfectly fine.

To access System Restore, open File Explorer and navigate to %windir%\system32\restore.exe. Click “Restore my Computer.”

You’ll see a list of options. Choose the option that best suits what you’d like to change. For example, if you’ve recently installed a program, you might want to select “Previous versions of selected programs,” rather than “Recover my computer.”

Once you’ve chosen the correct option, follow the prompts and let the process run. Once complete, you’ll have restored your computer to a previous state.

If you’re looking to troubleshoot a problem, try rolling back to a previous version. Or, if you’ve been experiencing crashes, you can restore your machine to a point prior to the crash.

Getting a repair/clean install done

A repair install will leave all of your programs intact while a complete clean install will remove them all. This makes it easier to perform a repair later if needed. If you are installing Windows 10 Home, a repair install will give you the option to keep your files and restore your settings. However, if you choose to do a clean install, you will lose all of those things.

If you want to use a repair install, make sure to backup your data before performing one. You can find instructions here.

Most Windows Update Error Code 646 Error Messages

A common error message seen for Microsoft Windows Update Error Code 647 is “Windows cannot connect to the server.”

This error occurs if an attempt is made to update Windows 10 Home Edition or Windows 8.1 Pro without having Internet connectivity.

To resolve this issue, check the status of your Wi-Fi connection. If it is disconnected, reconnect it. Then try updating again.

If you are still unable to successfully complete the update, contact your system manufacturer or technical support provider.

Why Windows Update Error Code 646 Occurs

When you receive a Windows Update error code 646, there are several possible reasons why. Some of those include:

1. Your computer does not meet the system requirements for installing Windows 10.

2. A problem occurred while downloading the latest update.

3. An incorrect version of Windows 10 was installed.

4. You did not install the latest security patches.

5. You did not complete the setup wizard.

6. You did not select the correct language settings.

Frequently Asked Questions

I don’t want to move up. What’s wrong with this version?

If you are using an older version of Windows 10, you might not be able to use some features or apps that are available on newer versions. For example, you won’t be able to get new apps from the Microsoft Store if you are using Windows 7 or 8. You won’t be able to get to some websites either, like Facebook and Twitter.

Can I stop Windows from updating or put it off?

You can skip Windows 10 updates if you want to. You will need to be running Windows 10 10240 or a later version. You can’t skip updates if you’re using Windows 7 or 8.1.