The videos have been created for viewing in Windows Media Player (WMP), but other players may also work.   If you don't already have it on your computer you can download WMP from this link.   Select the version for your operating system from the list in the left column of the page.

If your computer is running Windows XP, and you have Windows Media Player 9 Series, you have the ability to set play speed to 50% for slow motion, and to pause and then single frame advance and reverse.   To access those features select View>Enhancements>Play Speed Settings.   Another note, once the file is downloaded to WMP, you can save the file by selecting File>Save Media As and put it in any directory on your hard drive or other storage device.   Be sure to maintain the .wmv file name extension.   Alternatively, you can right-click on a video link, then select 'Save Target As', then select a location on your hard drive to save the file to.   Once on your hard drive, you can just double click the file name and it will play.