Although the 646 error will either randomly or continually show on a Windows system, it's actually caused by a common set of problems which need to be fixed in order to ensure your computer can run as smoothly and effectively as possible again.
This tutorial is going to show you the steps you can take to fix the error you're seeing, as well as how to prevent it from appearing again.
The 646 update error will often show when you try and use the Windows Update application to download updates for your PC.
The problem that causes the error is that your system either cannot correctly process the updates from the server, or it has some sort of problem with the settings / options of your PC.
This can either be caused by your FireWall blocking the connection to the update service, your PC having some "registry errors" or Windows not functioning correctly.
The way to resolve the 646 error is to first ensure that your PC is able to connect to the Internet, and that your FireWall is not set to block the "Windows Update" program.
This can be done by first temporarily disabling your firewall / antivirus program, and then clicking onto Google and typing a random search term into the box.
This will ensure that Windows will be able to correctly connect to the Internet and download the updates it requires.
After doing that, it's then recommended that you re-register the DLL files which Windows Update uses to run.
This is very important because since Windows Update is such as complicated program, it's continually using a huge number of files and settings to help it run.
Re-Registering the files that Windows Update requires will basically be like re-installing the application.
To do this, you should click onto "Start" and then select "Run".
After that, type "CMD" into the run box and you'll be able to re-register the files that Windows Update needs.
The final step to fix this error is to then use a registry cleaner application to fix any further errors with the files / settings of your computer.
A registry cleaner is a software tool which scans through the registry database of your PC and fixes any potential errors that are inside.
The registry is a large database which all Windows computers use to keep vital settings & information.
Although it is used continuously on Windows computers, the registry often causes a large number of errors for your PC, as it's will be corrupted & damaged.
To ensure this problem is not causing the 646 error, it's recommended you repair any potentially damaged registry settings with a registry cleaner program.