Has anyone determined how much memory the human brain has?

Obviously our brains are an organic computer running software. All that we are is software, right? Now I know that I must zip some files that I don’t need handily, certain memories for example. Other files that I use on a daily basis must be kept in my cache memory and be instantly available to me. But there has to be a point where files must be deleted to make room for more, don’t you think? Has anybody heard of any study regarding memory space in the human brain? If so, have they have an idea as to how much?