I have recently upgraded my Windows 8.1 to Windows 10. There are few bugs with Windows 10 and few of them are very annoying just like the one “Critical Error: Start menu and cortana aren’t working“. In this error your task bar will stop working, all the keyboard shortcuts which uses window key will stop working. There will be a pop up saying “Critical Error: Start menu and cortana aren’t working” and will ask you to sign out and sign in again to fix it. But signing out and signing back in, even restarting system after signing out is not gonna fix it.
This is because of the recent Windows update build 10240.
I searched on a lot and tried lot of things but finally found a workaround which I have mention below in steps:
1. Open up task manager by pressing Ctrl + Shift + Esc . (you won’t be able to do it from taskbar)
2. Click on File > Run new task
3. Write “msconfig” in the box and check the box which says “Create this task with administrative privileges”
4. Go to Boot tab in Boot options, enable “Safe boot” and select “Network”. After that hit Apply and OK and Restart the system.
5. Your computer will start in Safe Mode. Now repeat the steps again from 1 to 3 and uncheck Safe Boot in Step 4 and restart.
Hopefully, your critical error would be gone and start menu will work properly.
Microsoft has acknowledged the bug of critical error which I mentioned and working on a fix which will be coming soon.