How to Fix Windows Update Error Code 643

Windows 7 is one of the most loved operating systems released by Microsoft. Even though official support for it is going down in 2020, there are still many users that prefer and use it till this day. There are still updates released for Windows 7 which makes it even more competitive performance and features wise. However, in some case, you might come across some errors while trying to initiate an update. One of these errors is error code 643. This error is very generic and tends to come up now and then for someone. This is mainly caused by .NET framework corruption. That, however, is not the only cause it is restricted to i.e it can also be caused by software conflicts. We will be discussing the causes of the error code in more detail down below.  The error mainly occurs in Windows 7 but can occur in Windows 8 and 8.1 as well. Due to this error, your Windows will not update and you will not be able to get updates from Microsoft.

Windows Update Error 643

What causes the Windows Update Error Code 643?

The appearance of error code 643 refers to the update not being installed on the system due to some reasons. These are usually are:

  • Third-Party Antivirus Interference: The error code might appear due to the third-party antivirus on your system interfering with the update process. In such a scenario, you will have to temporarily turn off your antivirus software and then initiate the update.
  • .NET Framework Corruption: The main cause of the error seems to be a corruption in the installation of the .NET Framework. In such a case, you will have to uninstall the different versions of .NET Framework using a utility and then install them again.

There are many things you can do to get rid of this error. As we mentioned earlier, the error can be caused due to multiple reasons and the solutions vary as well then from one particular scenario to another. Anyway, you can try these solutions mentioned below. Hopefully, one or the other will work for you depending upon the cause of your problem.

Solution 1: Run Windows Update Troubleshooter

As this error restricts your Windows from updating so the first thing you can do is to download and run the Windows update troubleshooter to see if it can resolve the issue or tell you what steps you can take. To do that in Windows 7, 8 and 8.1, you have to download it first.

  1. Head over to this link and download the troubleshooter.
  2. Then once it has been downloaded, run it to from the directory you downloaded it to.
  3. Once it is opened, click on Advanced and click apply repairs automatically.
    Windows 7 Update Troubleshooter
  4. It will take some time if there are some repairs to be made.
  5. Once it finishes, your error might have been solved. If it doesn’t, you need to try the solutions below.

Solution 2: Remove and Reinstall Microsoft .NET Framework:

One of the things that can be causing this error is a corrupted Microsoft .NET Framework installation. The remedy is to uninstall or remove Microsoft .NET Framework completely and then reinstall it. To do that, you need to download the .NET Framework Clean up tool to uninstall all the .NET framework components and then reinstall it.

  1. Download the Microsoft .NET framework Clean up Utility from here. Then extract the zip file.
  2. Run the extracted file.
  3. Once you run it, you will see a window with different options, click on Cleanup Now. This will clean up and remove Microsoft .NET framework components completely from your system.
    .NET Framework Clean Up Utility
  4. After that go ahead and download Microsoft .NET Framework (latest version) from here and reinstall it.
  5. Once reinstalled, reboot your computer and hopefully, your problem would have been solved.

Solution 3: Turn off your Third-Party Antivirus

Many times, some features of the antivirus software can block Windows update from functioning correctly. If you are getting this error and not being able to update, you can try disabling your Antivirus software and give a go at Windows updating again. If it has been caused due to antivirus software blocking it, then it will run properly after you disable your antivirus software.

Disabling Antivirus

Solution 4: Repair Microsoft.Net Framework Client Profile:

A corrupted Microsoft Framework Client Profile can also, sometimes, result in the appearance of this error. The good thing is that Windows 7 users can repair the .NET Client Profile using the control panel. To do that,

  1. Go to Control Panel in Windows.
  2. Then open the Programs and Features applet.
    Windows 7 Control Panel
  3. In there, type “Microsoft .NET Framework” to list the .NET Framework installed on your system and click it to highlight them.
  4. Then click on Repair option and click on Next button.
  5. Once the repair has been finished, run the update to see if it has been resolved.

Kevin Arrows

Kevin Arrows is a highly experienced and knowledgeable technology specialist with over a decade of industry experience. He holds a Microsoft Certified Technology Specialist (MCTS) certification and has a deep passion for staying up-to-date on the latest tech developments. Kevin has written extensively on a wide range of tech-related topics, showcasing his expertise and knowledge in areas such as software development, cybersecurity, and cloud computing. His contributions to the tech field have been widely recognized and respected by his peers, and he is highly regarded for his ability to explain complex technical concepts in a clear and concise manner.