The second most recent was when Windows Store local repository become broken. Any attempt at resolving the issue failed using Windows provided tools. Yet again had to reinstall the OS and all applications.
This is the big reason why I prefer Linux over Windows any day of the week. Windows fix always seems to be the same, re-install OS and applications. Never had a problematic Linux installation that couldn't be resolved with a live CD / USB. Boot into live USB, mount encrypted partitions, chroot into environment, fix problematic package(s) or re-edit configuration files, reboot. No need to reinstall the OS and all applications.
Linux packaging system(s) are heaven compared to the Windows update hell-scale. Ever have to find a way to update the Root Certificates in order to install .NET Framework 4.7.2 offline on Windows 7 Embedded SP1 that is air gaped and has not had an update since the computers were shipped? Not fun.