I have personally been using Brothers Keeper for years, many years I have never had any problems with it at all. It is free to use and download but it is worth paying for the CD and the book. It is not expensive and it makes it easier to answer any questions you may have. I have also gotten some of the upgrades over the years but since I prefer to keep it simple, I have not worried about adding every update that has come along.
There are many other genealogy programs you can choose. At some point you will probably want to invest in one and since you can try this one for free, it is a good option. Here is a link to BKs website.