The only possible fix will have to come from Microsoft itself, the creator of this mess. Here is what I posted on the Microsoft Forum last week:
SHAME ON YOU, MICROSOFT:
There are hundreds if not thousands of worldwide posts already on the internet complaining about that major issue, that is the Critical Error-Start Menu and Cortana aren't working. We'll try to fix it the next time you sign in" (which of course doesn't work, what a joke!).
I have tried countless of so-called "solutions" found here and there on the net, including some suggested by your "brilliant" software engineers (who I suspect very well know the troubleshooting won't fix anything, which is quite insulting as far as I'm concerned), wasting hours and hours trying to figure out how to fix your mess, or even trying to revert back to Windows 7, all to no avail.
Man, I had a perfectly fine working Windows 7 before installing this piece of garbage. No wonder it's free!
MICROSOFT, you owe it to your customers to have your I.T. SWAT team work around the clock to come up with a fix ASAP via an update that automatically installs without having the end-user perform some complicated computational cyber-gymnastics to repair your useless catastrophic non-operating system.
You also owe it to your customers to keep us posted about development via press releases so we know what's going on and when exactly can we expect to get our computers back to normal. Anything less would show contempt and arrogance and will guarantee you a PR nightmare, you can be certain of that. Simply hiding behind some vague casual statements from a brain-washed spokesperson is not enough, such as this gem from last week:
"Microsoft has acknowledged the issue and Jen, who works for Microsoft, stated that they are looking into the matter and that a fix is on the way. We've fixed many of the underlying causes for this issue, but there are still some eluding us, and I'm sorry to hear that this is impacting you guys" (no kidding, Jen!)."We have telemetry and crash reports that we're watching for this."
Thanks for the update, Jen from Microsoft. So, Jen, any news since then?
Signed: An incredibly frustrated and angry customer