Beyond this being a tired argument, I think I should make a couple observations:
1. Even if you were to buy into big-bang cosmology (this is questionable), big-bang cosmology cannot be explained by reference to natural laws. According to those who advocate it, the laws of the universe were created by the big-bang. Consequently, the big-bang cannot explain the existence of the laws of the universe by the admission of those who advocate it.
2. Hawkings argument regarding the instrumentality of natural laws is irrelevant. As Aristotle would put it, instrumental causes are fine and dandy, but for instrumental causes to function, there must be a formal cause. This is something that the new Atheists don't get and I've said about evolution as well. Macro-evolution is, as modern genetics shows, pretty much impossible. But even if you bought into it, you couldn't escape design. Why? Because evolution is a process that has laws, structure and a goal. Consequently it has a design and therefore requires a designer. Similarly, all the natural laws that function as causes, are in fact designed and therefore need a formal cause and a designer.
3. In other words, put in the form of Aristotle's concept of cause, Hawkings wrongly views God as a single instrumental cause along with others. Since all instrumental causes are accounted for, then God is not necessary. The point I would make is that the whole thing doesn't make any sense without divine causation. God is the formal and final cause of everything. Each instrumental and material cause is designed and sustained by God the creator.