I experienced a problem this week-end to repair a Windows 10 computer (installed following an in place upgrade from 8.1); The PC is an ACER Aspire E15


Initially this PC has been upgraded without problem, but after a moment (several months in my case), the behavior

the new modern UI start menu cannot start

the search and cortana cannot start

the new Microsoft edge cannot start


After investigations and preliminary tests, here is my solution;

Open the Task manager.  Here’s a tip:  Press CTRL+Shift+ESC.
Click File > Run New Task
Make sure you have a check mark beside “Create this task with administrative privileges”

Type the following 4 commands at the CMD prompt one by one:
dism /online /cleanup-image /restorehealth
sfc /scannow
Get-AppXPackage -AllUsers |Where-Object {$_.InstallLocation -like “*SystemApps*”} | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\AppXManifest.xml”}
Close the window command prompt.

If the problem has not been solved at this step; do the next steps beloz:

Logon with another administrator’s user profile

Backup the data of the faulty user’s profile

Remove the user’s profile (and remove old folder under c:\users\<faulty user profile directory>)

Recreate a new user account and test. the Problem should be resolved at this step now.