Quick PowerShell function that I use in some scripts to overwrite tattooed registry settings from a prior WSUS implementation.

Clear-WSUSConfig.ps1

function Clear-WSUSConfig {
    Stop-Service wuauserv -force

    Set-ItemProperty -Path HKLM:SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU -Name UseWUServer -Value 0

    Start-Service wuauserv    
}