Hari,
Two things..
Doing a Google search on: wuauserv
We see the following - Repair or reinstall Windows Automatic Update service (wuauserv) not WSUS
http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Windows/XP/Q_22522876.html
Accessing Automatic Updates Configuration.
http://www.amset.info/windows/auto-updates.asp
The other thing is that you never instantiate the object for WMI in the original script - unless you are not showing all of the code.
HTH,
Kent
