I would have suggested the same as what mathan suggested.
So you tried repairing and re-installing Labview? Do you have additional features such as NI-DAQ or Vision, etc? Di d you re-install those?
I realize that SP3 is rather recent. I always wait a while before installing Service Packs from microsoft.. They never fully test them 😞
Was everything okay before installing SP3? I will do a search to see if others have complained about it..
RayR