Run as administrator, but still "requested registry access is not allowed" - powershell

Question

I have a Windows PowerShell script. I logged into Windows as an administrator and run the script with PowerShell running as an administrator, and it worked; I could see all the changes happen after running this script.
But I still get the red error message:
requested registry access is not allowed
which is driving me nuts.
Why am I getting this error and how can I make it go away?

Answer 1

If you run regedit and navigate to the key that you are trying to access with your script, you can right click on it and view the permissions. You can see on that key what permissions Administrator has (Full Control, Read, Special Permissions)

Answer 2

This PowerShell trick worked for me:
$Path = "SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.jpeg\UserChoice"
$SubKey = [Microsoft.Win32.Registry]::CurrentUser.OpenSubKey($Path, [Microsoft.Win32.RegistryKeyPermissionCheck]::ReadWriteSubTree, [System.Security.AccessControl.RegistryRights]::ChangePermissions)
$Acl = $SubKey.GetAccessControl()
$RemoveAcl = $Acl.Access | Where-Object {$_.AccessControlType -eq "Deny"}
$Acl.RemoveAccessRule($RemoveAcl)
$SubKey.SetAccessControl($Acl)
$SubKey.Close()
**in $Path ==> change this to your path (path after Root folder)
**in $SubKey ==> [Microsoft.Win32.Registry]::CurrentUser : change this to your needed root Registry path

Answer 3

Try as Local System via psexec
This here worked for me:
get psexec.exe from here: https://learn.microsoft.com/en-us/sysinternals/downloads/psexec
use psexec.exe -i -s powershell.exe to start a new interactive (-i parameter) powershell.exe window as user Local System (-s parameter).
Inside that new powershell window try your command again.