Hi guys,
Problem is fixed and all happy.
It was an issue with the base image and NTLM authentication itself.
All good.
Thanks for your help lovely community.
Btw: Marc drink some water 
Also,
One more suggestion if one can make
Recently N/w guy restarted switch and broke connection b/w hosts and persistent disk.
Persistent is :- NAS storage and I'm running Microsoft iSCSI software target to get to host
linked clones (dedicated assignment), replica, vswap & disposable is living in Fusion IO.
persistent disk includes large PST files and roaming user data.
hosts couldn't restore iSCSI upon switch restart.
Anyways, restarted MSFT and all worked fine.
All VDI sessions were hung and we had to manually restart all the clones through vSphere.
Question is:-
With the current configuration what can be done to improve the environment and break dependency on persistent disk.
Meanwhile, we are already considering SAN for linked clones and persistent data.
PST is not that important in an our environment and we can resync in an event of loss.
How about if we keep persistent data in IO Fusion also and clear catch upon user log off and redirect PST through GPO to shared location (may be persistent disk).
can we this way we can break dependency upon persistent disk and create non dedicated assignment.
Thanks,
Matt