This error may occur when the MSI software update registration has been corrupted or if .Net Framework installation on the system has been corrupted. If this error is there in your system then you can fix this error very easily with the help of the given steps. Follow the steps to fix installation error 0X80070643 in .NET Framework.
Steps to resolve error 0x80070643 in .NET Framework:
Method 1: Fix MSI software update registration corruption issues:
In order to fix MSI software update registration corruption issues automatically, click on ‘Fix it’ button and then click Run in View Download dialog box. Visit Windows Update and try to install updates again. Reinstall.Net Framework updates.
If the problem is not resolved go to method 2.
Method 2: Repair the .Net Framework:
Download Microsoft.Net Framework Repair Tool to repair the listed version of.Net Framework and then reinstall.Net Framework update: The .NET Framework 4, The .NET Framework 3.5 SP1, The .NET Framework 3.0 SP2 and The .NET Framework 2.0 SP2. If the issue is not resolved or you are using another version then move to method 3.
Method 3: Uninstall and reinstall .NET Framework:
.NET Framework Cleanup Tool will help you to uninstall multiple version of .NET Framework and reinstall the components. Follow the steps:
i) Check .NET Framework Cleanup Tool User’s Guide.
ii) Download .NET Framework cleanup tool.
iii) Click Open when prompted and click on Extract Now.
iv) Double-click the file “cleanup_tool.exe” you extracted.
v) Click Yes if you are asking for a question “Do you want to run the .NET Framework Setup Cleanup Utility?”
vi) Click Yes to complete license agreement.
vii) In ‘Product to clean up’ window click on the list and select ‘.NET Framework- All Versions’ and then Cleanup Now.
viii) When the .NET Framework is removed restart your system.
ix) Download and install any of the components (The .NET Framework 1.1, The .NET Framework 1.1 Service Pack 1 or The .NET Framework 3.5 Service Pack 1).
x) Restart the system.
xi) Visit Windows Update again and then check for and install updates.
xii) Reinstall .NET Framework update.
The above steps will help you to Fix Installation error 0X80070643 in .NET Framework. You can also use third-party tool Advanced System Repair Tool which is specially designed to remove the windows error.