Recently my Windows 10 was upgraded but apps don't work

Recently upgraded my Windows laptop to Version 2004/OS Build 19041.45.

Before upgrade I had a whole lot of stuff on the Desktop. They are all gone (I am sure hiding somewhere). Now I have a couple of shortcuts.
In the Start program, I have many apps that do not start including the Microsoft Store. How do I restore their functionality?

However, this idea worked. I created a new user for the windows and when logged in as the new user all apps are totally functional. This is just a temporary work around. I want a permanent solution.
I have also tried to tweak BackgroundIntelligentTransferService. That did not solved the problem. I tried PowerShell.
This command works:
PS C:\Users\TEMP> Get-AppxPackage Microsoft.WindowsCalculator
But this throws an exception:
PS C:\Users\TEMP> Get-AppxPackage -AllUsers
Get-AppxPackage : Access is denied.
Access is denied.
At line:1 char:1
+ Get-AppxPackage -AllUsers
+ ~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Get-AppxPackage], UnauthorizedAccessException
+ FullyQualifiedErrorId : System.UnauthorizedAccessException,Microsoft.Windows.Appx.PackageManager.Commands.GetAppxPackageComm and
Is there a EASY way?

mysorian said:

Recently upgraded my Windows laptop to Version 2004/OS Build 19041.45.
Before upgrade I had a whole lot of stuff on the Desktop. They are all gone (I am sure hiding somewhere). Now I have a couple of shortcuts.
In the Start program, I have many apps that do not start including the Microsoft Store. How do I restore their functionality?

However, this idea worked. I created a new user for the windows and when logged in as the new user all apps are totally functional. This is just a temporary work around. I want a permanent solution.

It's good that you tested with a new account, that shows the problem is only there when you sign in with your main account. The missing stuff from the desktop suggests you may have been signed in with a temporary profile. See if this tutorial helps.

Fix You've been signed in with a temporary profile in Windows 10

Does the following work?

Windows Key+X > Windows Powershell (Admin) > Copy the following from below and right click in Powershell to paste > Enter

Get-AppxPackage -allusers *WindowsStore* | Remove-AppxPackage

Copy the following from below and right click in Powershell to paste > Enter > Reboot your computer

Get-AppxPackage -allusers *WindowsStore* | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\AppXManifest.xml”}
========================================================

These lines can be run:
Set-ExecutionPolicy -ExecutionPolicy Unrestricted
Get-AppxPackage -AllUsers *WindowsStore* | Remove-AppxPackage