NET Framework error code 0x643.

My computer has been trying to install .NET Framework 3.5SP1 and Family Update for several weeks now and a message says it has not been installed.  Today I got a serious error message that sent me to a link to ensure that all my critical updates have been installed.  It appears this NET Framework is a critical update.  The error code is 0x643.  What do I need to do to get this update installed?

Question Info

Last updated March 30, 2018 Views 109 Applies to:


·         Apart from this update are you able to install other updates on the system without any issues?


I would suggest you to follow the steps mentioned in the article given below and let us know whether the issue is resolved.

When you try to install an update for the .NET Framework 1.0, 1.1, 2.0, 3.0, or 3.5, you may receive Windows Update error code "0x643" or Windows Installer error code "1603"


Thank you and Regards.

Thahaseena M
Microsoft Answers Support Engineer.

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