Why I can't view file preview?

My Vista won't show the file preview, does anyone know how to fix this? I attached the picture, the one on the left is what I have in mind. Thanks for the input.

 

i honestly cant say i know alot about vista and i dont know if this will work but it might be worth a shot

http://www.videolan.org/

perhaps try that

good luck

Wolf

 

See, when I open the folder in Vista one video file shows correctly and the other one is just displayed as a plain icon with AVI written under it. Now, what I want to do is show the preview of the video file before I even open it (as shown on in the picture on the left) My problem is certain files show exactly as intended while others are only icon, how come?