How do i record my computer screen [duplicate]

Possible Duplicate:
What is the best software for desktop recording?

i want to record my computer screen and talk over it. i have seen this done on youtube and i want to use this for my family. Are they just using a regular video recorder on a tripod?

Camstudio its a free software you install and pretty easy to use

Well actually Camtasia Studio isn't free (you actually get it for 60 days) and the rendering is a bit pixelated. You should try Microsoft Expression Encoder. The video recording is Super Clean and to get a free copy just register as a student on DreamSpark.