You sad sacks are depressing. Of course we do. By 'we' I include the forces inherent in biology and everything sub-ego. Regardless of what actually happens, I have the ability to do anything in the realm of possibility. You might say the realm of possibility extinguishes free will but just because you are limited does not mean you are without will. Evolution might have determined everything I am, but I determine everything I can be.
I have free will. Do humans have free will? Depends on if you have any faith to believe in what you cannot see. And no I'm not talking about 'God'- I'm talking about faith in your ability as a human to act independently.
There will be no proof that we are acting on anything other than what can be seen, what can be rationalized, but the very belief that we have free will, proves free will.