.NET Framework update installation error: "0x80070643" or "0x643"

This issue may occur if the MSI software update registration has become corrupted, or if the .NET Framework installation on the computer has become corrupted.


To resolve this issue, try one or more of the following methods in the order they are listed.

Note This article does not apply to Windows 8 or later.

Download the Microsoft .NET Framework Repair Tool to repair the following versions of the .NET Framework, and then reinstall the .NET Framework update:
  • The .NET Framework 4
  • The .NET Framework 3.5 SP1
  • The .NET Framework 3.0 SP2
  • The .NET Framework 2.0 SP2
For more information, see Version 2 of the Microsoft .NET Framework repair tool is available. If the issue is not resolved, or if you are using other versions of the .NET Framework, go to method 2.  
Use the .NET Framework Cleanup Tool to uninstall multiple versions of the .NET Framework, and then reinstall the components.

To do this, follow these steps:
  1. Check out the .NET Framework Cleanup Tool User's Guide.
  2. Download the .NET Framework cleanup tool.
  3. When you are prompted, click Open, and then click Extract Now.
  4. In the files that you extracted, double-click cleanup_tool.exe.
    If you are prompted for an administrator password or for confirmation, provide the password, and then click Continue.
  5. In the Do you want to run the .NET Framework Setup Cleanup Utility? message, click Yes.
  6. Click Yes to accept the license agreement.
  7. In the Product to cleanup window, click the list, select .NET Framework - All Versions, and then click Cleanup Now.
    Note The cleanup tool does not let you remove the .NET Framework 2.0 in Windows Vista or later versions of Windows because the .NET Framework is installed as an operating system component.
  8. After the .NET Framework is removed, restart the computer.
  9. Download and install the following components:
    The .NET Framework 1.1

    The .NET Framework 1.1 Service Pack 1 (SP1)

    The .NET Framework 3.5 Service Pack 1 (this will also install the .NET Framework 2.0 SP2 and the .NET Framework 3.0 SP2)
  10. Restart the computer.
  11. Visit Windows Update again, and then check for and install updates.
  12. Try to reinstall the .NET Framework update.

More Information

You may also experience the following issues when you install .NET Framework updates:
  • The update is not installed.
  • The system keeps reminding you to install this update even though you have already installed it.
  • The desktop does not appear.
If you experience one of these issues, try the following methods to resolve the issue.

Method 1: Download the update from the download link and install it in clean boot mode 
Method 1: Download the update from the download link and install it in clean boot mode 

Article ID: 976982 - Last Review: Aug 5, 2016 - Revision: 1