Solved another update problem

updates remain working BUT KB5015814 and it's replacement KB5015882 (this per W11 update catalog) will not install generating error 0x80073701. I have done all the suggested fixes finally including an in-place upgrade which faults and rollsback during installation of updates I think the same updates above?
Any suggestions please.
Thanks
Dave

I had the same problem on 2 PCs. On this one (my main rig), things went south drastically and I ended up having to do a clean install. On the 2nd PC, I uninstalled Malwarebytes and turned off .NET Framework 3.5 (includes .NET 2.0 and 3.0). I was then able to install the update KB5015814, reinstall Malwarebytes and turn .NET Framework back on

Thanks tw33k
I will try your solution and report back!
Dave

Sometimes updates don't install because they are replaced by newer updates. If you have installed a newer update that does the same thing, you cannot install the older update. Searching for updates again should remove the obsolete updates from the list, if that is your case.

My report on attempting tw33k's solution... It worked! The first to resolve was KB5015814. It previously had dounloaded with very few download status updates then a jump to 25% installed and then another jump to 35% and shortly thereafter faulting to the 0x80073701 error. I had seen several online reports of similar behavior. Then about a week later the KB 5015882 showed up and ms update catalog described it as a replacement for KB5015814. However, it behaved in exactly the same manner as KB5015814 had. Finally, after making tw33k's changes KB5015814 loaded but took close to 20 minutes to install, reboot then the second update KB5015882 installed but much quicker. System is now stable.
Thanks again to tw33k for sharing your fix!