Solution to 'Critical Error Start Menu and Cortana aren't Working'


Many users have been having this critical error, and it seemed rather upsetting as it is barely less than a week since the release of the Windows 10 and a serious bug like this shows up. The full error reads:
"Start Menu and Cortana aren't working. We'll try to fix it the next time you sign in. Sign out now:
After frequent signing out, it couldn't fix itself, so I had to try solving it myself. Noteworthy is, while this error is displayed, nothing on the desktop, or taskbar, or even start menu can be interacted with, but your O.S is still full functional, it's just the WindowsExplorer.exe file that is misbehaving.

Solution: 

Of the several possible solutions that came to mind, the first I tried worked perfectly. Here it is:
  • Hold Ctrl + Shift + Esc to bring up Task Manager (NB: tast manager's file->run new task seemed to not be able to bootstrap any program)
  • Locate Windows Explorer under processes
  • Right click "Windows Explorer"and click on open file location (This will open an explorer window in the directory C:\Windows\. You can also close the Windows Explorer process and right any other process and click on open file location.
  • Go to C:\Windows\System32
  • Right click cmd and run as administrator
  • in cmd enter:  sfc /scannow
  • Wait for the scan and restart