I don't believe that it's in general possible to prove or disprove God's existence and indeed there are many, many scientists who are also religious and would generally argue that there is not a contradiction, or perhaps that their Science enhances their faith. Equally there are many Scientists who are atheist, perhaps because understanding the Universe better can lead to questioning why it's all here for us or some such. Basically, I think people see in Science what they want to see when it comes to religion.
What I DO believe is that Science, as far as it goes, is correct and the best system we have for understanding how our Universe works. This can of course sit comfortably alongside the "Why" of religion. But there is a big "BUT". Which works something like this:
1. Scientific study has led to fact A being true to a high degree of probability.
2. My interpretation of religion appears to work only if Fact A is false.
3. Therefore we have arrived at a contradiction between Science, whose work leads inevitably to A, and religion.
While this isn't using Science to disprove God in general, it does mean that certain interpretations of religion are surely false. The question then is whether or not that interpretation is the correct one.
So my views on this question are that Scientific facts are the closest to certain knowledge we can practically get, but that the question of existence or non-existence of God is primarily a religious question. Science enters in only at the very end, and only if a religious view finds itself in disagreement with Science.