XiaoDeer wrote:

It seems many people are experiencing Error 0x80070643 when installing KB5034441.

Apparently, it means that the recovery partition is too small. They want users to do this:

https://support.microsoft.com/en-gb/topic/kb5028997-instructions-to-manually-resize-your-partition-to-install-the-winre-update-400faa27-9343-461c-ada9-24c8229763bf

Yikes. How many folks will be able to manage that?

The consensus in other forums seems to be to wait until MS issue new guidance and/or a new update.

See this thread to fix it https://www.tenforums.com/windows-10-news/210321-kb5034441-security-update-windows-10-21h2-22h2-jan-9-a.html

If you are unsure what to do I would wait for MS to fix the problem.