Except that is fundamentally wrong, and your example is also wrong as well. We all know what makes up inside of a computer, (if you don't that's your choice not to but the information is freely anywhere on the net and you can take one apart yourself to figure out the details.) But there is a big difference between belief in abstraction and nigh-tangible and what is tangible. I can take apart a computer and show you how it works, there are those out there even greater than I which can show you how the basis of how electricity flows through a circuit board and how the flipping of bits creates mathematical processes. Its all right there in front of you. You or I cannot explain the fundamentals for our reality however, the basis of it or how it came to be. Yes the big bang is a tangible theory but it also does not answer how that happened prior to its existence or how it all came to be to create us in the here and now. Whether you believe in the traditional sense of God or a general Creator theory the fact is either way you look at it, there is no truth to be better explained when the truth has not been proven yet.Most atheists reject religious claims because those claims have not met their burdens of proof. Atheism is not a positive claim, and it isn't a "belief."
I don't believe in magical pixies that live in my computer case and cause every typo I seemingly make, and the reason why is because there's no evidence for the existence of those pixies. I have a feeling you also don't believe those pixies exist, and I have a feeling that it's also because there's no evidence demonstrating the existence of those pixies. Believing in the pixies and not believing in the pixies are not comparable positions: One is rational, and the other is not.
Atheism is the same way.
In short, if you cannot for a matter of a fact prove your position to be true on fact alone, then it is a belief stated only in theory, which makes atheism no different, or better than any other traditional religion out there. When there is no factual answer for the big questions in life and insist your theories are correct, you are doing no different than any other overly religious person would do and push your beliefs onto others because you are right in your belief. When there is no proven fact one way or another, it is a belief, a theory, whatever you want to call it. Its not substantial enough to separate you from them as it still falls on the structure of belief. You believe its rational, just as those believing in God are rational to themselves.
Atheism is a religion just the same.