Where Stephen Hawkings is now ... we don't know. God will decide. When Billy Graham died, many said that he, too, was in Hell because towards the end of his life, he became more inclusive. He stated that people of others faiths, or no faith at all, might be saved IF they lived as if they knew Jesus (paraphrasing).
I cannot judge anyone's soul. I certainly dont believe that people of other religions (and possibly no religion at all) will go to Hell because they believed in the wrong "things". I wonder if there even is a Hell.