I see that zaman25 has found a solution in Camtasia, but just in case anyone may be looking for an alternative program for recording their screen (with voice/audio), I'd also recommend Movie Edit Pro Plus. While it's designed more for doing video editing, the Plus version has a screen recorder that I've been very happy with, having used it to record a few of my latest ArtRage tutorials. It can be adjusted to record the full screen or just certain areas. There's also an option to upload the edited videos directly from the program into YouTube (and other popular online video hosting sites), to help remove the guess work needed in getting the best resulting compressions for online viewing.
Nothing is easy to the unwilling.