Thank you for the reply!
SCCM 2012 has an inbuilt feature where in patches coming from MS will be loaded on to the old WIM and a new WIM with updated patches will hatch. With this we are disturbing the WIM which we created previously. I am looking for a solution where in WIM is not touched while pushing updates to the OS and these updates should be loaded offline and not when the OS has booted for the first time(Before the login screen comes). Is there a way we can load these patches offline?
Vasu