Take a series of screenshots automatically at regular intervals, with Automatic Screenshoter
Automatic Screenshoter is a free and efficient utility that remains unnoticed at the system tray and takes screenshots at interval you can define according to your needs.
A very nice feature of Automatic Screenshoter is its ability to recognize running programs and (if you decide so) stop taking screenshots when a particular program is running, or even take screenshots only of particular programs.
There are some more conditions of screen capture, such as stop taking screenshots when you activate a screen saver or use a full screen app or game.
Note that the program supports multiple monitor setups and is able to delete screenshots automatically after a time limit you can define, etc.