That again is an inaccurate way to put it. Microsoft is under no obligation to provide support for Classic Shell related issues, but that does not make the Windows installation unsupported. They are still under obligation to provide support for Windows 8 even if Classic Shell is installed. Classic Shell is just like a regular app, it does not depend on any Microsoft code, it is 100% its own code. Microsoft can't totally break it via Windows Update, stop spreading FUD. Do you go around saying installing Visual Studio or Microsoft Office or Steam or Firefox or Google Chrome makes Windows unsupported and that they can break it via Windows Update? Windows updates can break only if for those applications which modify system files or system settings or which use undocumented hacks/methods to incorrectly modify the system.. Classic Shell does not touch system files or system registry settings.
I'm not even sure what you're trying to say anymore. I never said that installing classic shell makes Windows itself unsupported. Only that modifying the shell with something like Classic Start is not supported *by* microsoft. Windows update can and will make some serious changes that affect the way applications work. Those applications then need to be updated to work with/around those changes. Its not an uncommon thing, especially in the business world where proprietary software can be extremely sensitive to the OS environment. There's a reason things like WSUS exist and IT departments test and test before deploying updates instead of just turning on auto-update for everyone. likewise, applications can interfere with Windows itself. If some app developer decides to use the Windows directory to store things with identical filenames and Windows update goes to update the overwritten files, you can bet its not gonna work right.
You seem a little... unstable about all of this, and we've already determined that the OP doesnt even have Classic Shell installed, so i'm just gonna leave it at that. It's off topic.
I agree with Ketchup, we're pretty much at the point where it's faster and easier to just wipe it clean and start fresh instead of wasting more time chasing phantoms. It happens, and if the same update fails afterwards then there's definitely something else going on.