For all I know, I might be asking this question to programmed beings.
According to the argument from analogy, I infer the existence of mental states in other people, by analogy with myself. Just as I observe a correlation of my own behavior with my mental states, so I can infer the presence of appropriate mental states in others when I observe their behavior. I have already pointed out the limitations of this form of argument. The problem is that in general with inferential knowledge there must be some independent check on the inference if the inference is to be valid. Thus, for example, I might discover that a container is empty by banging on the container and inferring from the hollow sound that there is nothing in it, but this inferential form of knowledge only makes sense given the assumption that I could open up the container and look inside and thus noninferentially perceive that the container is empty. But in the case of knowledge of other minds there is no noninferential check on my inference from behavior to mental states, no way that I can look inside the container to see if there is something there.
By John Searle, from his book Mind - A Brief Introduction, page 23: The Problem of Other Minds
We cannot know from any observed behaviour that another person is conscious. This is the 'other minds' problem and it is well known. There may be other ways to know but if there are they lie outside of the natural sciences. The natural sciences cannot establish the existence of consciousness. It is reliant on untestable first-person reports.
Dao De Jing, chapter 58, says:
祸兮福之所倚 福兮祸之所伏 孰知其极 其无正也
Which may be translated as:
Disgrace brings luck on its side, beyond luck disgrace is hidden. Who knows how will this end? There are no certainties.
The point here is: there are no certainties. You can never be sure, so solipsism is still a possibility. However, if you're alone in the world, this brings two practical problems:
1) Your existence would be somewhat miserable, wouldn't it? To think that every moment, since you were born, since you breastfed in your mother, you were always alone, is very... empty! The emotional on us, our instincts, surely deny this. And intuition is a very strong form of knowledge.
2) Looking through parcimony, it's easier to accept that other people like us exist (materialistic view) than to think they're all some kind of dream (idealistic/metaphysical view). I don't see any good reasons why a metaphysical view should be more important than a material, sensorial view.
JimmyJames nailed it in his comment. Any discussion of the nature of consciousness is irrelevant. To prove something "for sure" is establishing a level of certainty at 100%. Consciousness requires existence. Can you prove at 100% that I exist? I think that you cannot. Therefore, you cannot prove at 100% that I am conscious.
Consciousness is a spectrum, all things having some amount of it. Even things we perceive as inanimate objects still have some, but just a relatively smaller amount. Consider an atom of your brain, on its own it does not appear to have any consciousness, but you have consciousness, therefore a fraction of your consciousness is coming from that atom. You can come up with levels of consciousness all the way up to the top and down to the bottom.
Your own personal consciousness acts as a component to many larger consciousnesses. If, for example, you work for a company, then the things you do effect what the company does. The things you observe make up part of the observation capability of your company. Similarly, components of your brain are making different observations and directions, giving you consciousness when they are combined as a whole.
At the very top, you would see that the universe itself has at least some degree of consciousness because of you, considering that your observations, thoughts, and actions effectively alter the "decisions" the universe makes. Your impact as an individual is relatively small, and the universe is doing a lot of things that you do not know about, so the rest of the universe's consciousness must come from others.
To address your specific uncertainty as to whether we are programmed beings, my thought is that it would not matter. As long as each of us act as a component of a larger consciousness, then we each have our own consciousness, even if we are characters in your dream, multiple personalities, or whatever. The only thing that changes is the relationship between our consciousnesses and yours.
I suppose my answer looks weak without references... I don't believe anyone who wrote previous works has a special window to know more about consciousness than anyone else. The logic of the contents should make a far better gauge.