How to resolve Code 646 Windows update error

Windows update allow the users to install the latest updates from Microsoft and also third party providers. It is not entirely perfect and some error can restrict from installing the updates. Code 646 is one of such error, which popups when you are trying to update Microsoft Office. If you are facing this error, don’t worry, here are the solutions to resolve this error.

How to resolve Code 646 Windows update error

Method 1: Using Microsoft Fix it


Using Microsoft Fix it is the simple and fastest method to resolve code 646 error. For this you need to run Microsoft Fix It  and follow the on screen instructions till end. That’s it, after finishing the installing, try installing the update once again and it should go through without any issue. If this method doesn’t work for you, then follow below methods, but they require more effort.

Method 2: Windows Update Troubleshooter

Search for find and fix problems and click on the exact result from the results, then you will be taken to control panel. Here click on the Fix problems with Windows update option. This will open a wizard and here click on Advanced and then select Run as Administrator option and click on Next to proceed further.

If any errors to be fixed, then they will applied automatically. Now try to install the update again and check whether Code 646 has been resolved or not. If the error is not fixed yet, then use the below method.

Method 3: Edit Registry

In this method you need to edit the registry, so you need to perform this carefully. If anything goes wrong then this may cause serious issues to your system. Follow the instructions carefully, to perform the registry editing successfully. This is the manual method for the first method which we have listed. If you perform this fix manually can achieve good results than automated application.

  • Press Win+R keys to launch RUN dialog box and type regedit and press enter, this will open Registry Editor.


  • In registry editor navigate to the following key,
    HKEY_USERS.DEFAULTSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders
  • Now in the right pane, double click on the AppData key to open edit string box and here in the Value Data box, enter the following.
  • Then click on OK and run the Windows update to check whether the issue is resolved or not. If this is not solved, then edit the registry strings in the below keys and input the same Value Data as shown above.

    HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders

    HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders

Though Windows Update can be bothersome, but this offers very useful function. Windows updates can even update the old hardware with the drivers which are impossible to find on the internet. There are lot of errors you encounter on Windows, but code 646 is the very easy to solve and this problem persists due to the Microsoft Office update.

This is how to resolve the code 646 error.

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