Science and philosophy are inconclusive (no surprises there).
Philosophy cannot even successfully define free will. What is free, and what is willpower? A common thought experiment is this:
>in an empty space
>come across a fork in the road
>no indication whether right or left is the correct path
>which do you choose?
I'm paraphrasing a philosophy paper I read for uni a while ago, but you get the idea. Or perhaps you thought about it yourself before. Here's the problem:
Being capable of making a "choice" in this situation where there are no outside factors to influence the decision is not necessarily a good indication of free will. Because you do not care about the outcome, it only proves your ability to choose randomly. Whereas if you DO care about the outcome, then your choice is determined by your ability to assess the situation and act in your best interest. In other words, a choice cannot technically be free, nor willed. Even when you are obviously making a choice free from constraints.
However, the question of free will did not emerge from nowhere and it cannot be so easily dismissed either. At the end of the day, there is someone in your head who is doing some thinking, and he is capable of wasting his time thinking about free will. What is the purpose of this thought, if it is incapable of influencing the world around it and is merely along for the ride like on a rollercoaster? Obviously we would not have evolved to have such a vast consciousness if it serves no purpose. It must be involved in making decisions, in deliberating.
However, we just established that there is no such thing as a decision, and that sends us into a bit of an infinite loop. Even the phrase "I have thought about it, and concluded that I am not free" is a contradiction in terms.