Hi all following this thread.
Like you all, I had no joy with the KB 5104668 update, it would download but only get to 25% install. I tried the suggested fixes in these posts but none worked, so I created my own thread and was answered by Jerico T. who after two suggestions came up with downloading an ISO Win 11 file and doing a clean/repair install of Win 11 64 bit, it fixed the problem and after some time downloading and installing the ISO file.
I was also running Malwarebytes and Bitdefender anti-virus, Jerico gave me a link that says not to run multiple anti-virus programs at once. I have used both programs since Win 7, but decided to uninstall both programs before doing the ISO Win 11 fix. I will reinstall one of the third party anti-virus programs later.
Here is a cut and paste of Jerico's post with the download link for Windows 11 ISO file if you want to try it.