check if you are using wsus
First you need to check if the computer is updating via the wsus server.
Run Powershell as Administrator and run these commands :
$MUSM = New-Object -ComObject "Microsoft.Update.ServiceManager". $MUSM.Services.
Check the output : if you are reading Windows Server Update Service
it’s the signal that source of updates is a wsus server.
Remove wsus from computer client
Run regedit.
Sarch for the folder
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\
Delete the entire folder WindowsUpdate.
Run services
restart windows update service.
You can repeat the test of the first part to check if wsus has been removed from the client.