How to verify if Windows Update location is properly configured from WSUS?

If you're using Group Policy to configure your updates, you can query the registry for the Target Group and WSUS server values:

C:\> REG QUERY "HKLM\Software\Policies\Microsoft\Windows\WindowsUpdate"
  WUServer    REG_SZ    http://fcsd-sccm
  WUStatusServer    REG_SZ    http://fcsd-sccm
  TargetGroupEnabled    REG_DWORD    0x1
  TargetGroup    REG_SZ    Servers

Or just get the WUServer value alone:

C:> REG QUERY "HKLM\Software\Policies\Microsoft\Windows\WindowsUpdate" /v "WUServer"
  WUServer    REG_SZ    http://fcsd-sccm

If the WUServer value is not present, you're connecting to Microsoft.

source: http://serverfault.com/questions/361184/how-to-verify-if-windows-update-location-is-properly-configured-from-wsus