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Computer error code 646 – How do I fix error code 646 for Windows update?

Posted by in Blog Windows update errors
on November 10th, 2012 | Leave a comment

“How do I fix error code 646 for Windows update?” Many users have ever asked themselves this question while using the computer because it is quite common for them to get such error while automatically or manually installing some Windows updates. Typically, the error message usually looks like this:
“Error Code: 0X80070646; Windows Update has encountered an unknown error” or
“Error Code: 646; Windows Update has encountered an unknown error”

Windows update error 646

No matter it is error code 646 or 0X80070646, they are all generated when the Windows Installer encounters an error.

When the computer error code 646 shows up frequently, check and make sure that your Firewall is not stopping you from installing some programs or updates on the PC. If you’re using McAfee Personal Firewall Plus, F-Secure Internet Security, Norton Internet Security or some another Firewall programs, look for its respective support page for assistance to temporarily disable it and then try another Windows update install. If you’re using the Windows built-in Firewall, follow these steps to continue.

* Go to Start, Control Panel and select Security.
* Select Turn Windows Firewall on or off.
* Select the “Off (not recommended)” option, click Apply and then OK to save your settings.
* Back to the Windows Update screen, click the Try again button.
* Then, the download(s) and installation should start…and you can follow the on-screen steps to install the updates successfully on your PC without an error code 646 anymore.

If this step does not solve the computer error code 646, it might be caused by an invalid entry within the registry database. By the way, registry errors can also bring some other Windows update error codes such as update error 80072ee2 or error code 80070643. At this time, you can follow the below instructions to go:
1) Go to Start, Run, type regedit in the box and then click OK to continue.
2) Locate and then click the following registry subkey:
HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
3) Locate AppData within this folder. By the way, the value of this key should be %USERPROFILE%\Application Data.
4) If the value is not set to %USERPROFILE%\Application Data, right-click AppData to select Modify.
5) Then enter %USERPROFILE%\Application Data within the Value data box and then click OK.
6) Quit the Registry Editor.
7) Try to install the update again to see whether the annoying error code 646 has been resolved or not. If the problem persists, repeat the above steps; but at this time, you should check the following subkeys rather than the subkey mentioned in step 2:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

However, if you are not a computer technician do not manually modify Windows registry database. Acting as the main component of the Windows-based operating system, registry stores all the settings & information of the software & hardware on the PC. Only when it is clean and compact, can the computer access it smoothly and perform every PC task correctly. If you mistakenly delete a wrong one, more serious problem instead of the computer error code 646 will come on the neck of another. It is best that you can rely on a trusted registry cleaning tool to completely scan the whole PC and get rid of all errors inside. Such tool is well designed to completely scan the whole PC and automatically repair all registry errors within minutes.

Just take it easy when encountering the Windows update error code 646 in installing some updates! With the simple above steps and registry modification processes, you can easily troubleshoot and deal with error code 646 the most effective way.

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