The following screen recorder is even better and easier to use the than the one that was recommended in a previous post. It's called Icecream Screen Recorder.
It is a free tool that enables you to capture any area of your screen either as a screenshot or a video file. The intuitive and easy-to-use software offers a complete suite of tools and options for professional screen capture with audio. With their screen recording software you can record webinars, games and Skype videos in HD, and much more in a quick and hassle-free way.
There is also a Pro version available for $29.95.
Besides its simplicity, it records any audio extremely well. Highly recommended!