Reconnect the Wsus...
you need to delete the identification info from the registry and reboot the PC in order for it to report properly. Here is the relevant information:

HKLM\Software\Microsoft\Windows\CurrentVersion\Windowsupdate
Delete the following entries, if present:
AccountDomainSID
SusClientID
PingID

Reboot.

The appropriate entries will be recreated when the PC reconnects to WUS.