Capping DVDs

The other day someone posted something about the 'cap' feature on Win DVD. It looks like a little film camera on the main menu (on mine anyway). Now the problem is, I can see it, but I can't use it.. (it's not clickable)

Is it because the DVDs I'm watching are encoded? Or am I doing something wrong? If the first is the case, is there any way to cap encoded DVDs?

EDIT: I guess my version just doesn't support it, but found a link to download Media Player Classic which caps like a charm and I'm a happy girly!!