BSS Screen Capture is a utility designed to aid in both tracking what happens on your computer and providing a handy way to review your own actions. It sits in the background and takes screenshots to JPG files at intervals you specify. It's specifically designed to prevent shutting off the screen captures inadvertently; the user can pause the captures for a specific amount of time but not pause them permanently (unless they close the program).
||Free to try
Windows Server 2008