The on-screen keyboard on my laptop seems to be easy enough to use. I tried it out for a short time before I shut it down. A small keyboard appeared at the bottom of my screen, and I could then use my mouse to type the letters as if I were typing with my fingers. The on-screen keyboard definitely does not work as fast as the regular keyboard, but if you have problems typing, this is definitely something that will make your life a whole lot easier. Perhaps the only thing easier would be voice recognition software, but even that has its problems.
Though I am not sure, I think you may be able to get software for an on-screen keyboard even if it does not come with your computer. Though I think most new computers to come with this program, if you have an older one, you should call your computer manufacturer to see if they have any of these programs available.