Well, in defense of the "teachers", we do not (generally) "smack your hands" for asking a stupid question. We "smack" them if you ask a question that goes against the rules.
And that's different. (by the by, the rules are available as an announcement if you wanna get familiar with the etiquette).
In a utopia, forums would be equal for everyone and there would be no need for advantages and/or somebody playing "police".
The thing is that the world ain't perfect (it's the latest theory...) so members have more privileges than guests and moderators have some more functions that members (administrator(s) are Forum Gods so we don't talk about them much).
What I'm desperately trying to say is that if there wasn't someone here to play the part of the "teacher", chaos would surely be unleashed upon GnutellaForums.com: guests posting all kinds of spam, flame-wars and other annoying stuff that can be witnessed in some other forums (mainly because they have section for it too).
We're more like Santa (hmm, maybe not): we know if you've been bad or good. (So be good for goodness' sake!)

Returning to the problem posted in the title post, are you sure that you have the right codecs?
Generally, you can view (almost) anything with the necessary codecs, so even if a movie won' t preview (which it should, methinks), make sure that you have the right codecs to play it; the completed file should play.
You can download the nimo pack that contains most codecs for Windows Media Player for PC, but I suggest you just switch players to the free and less dangerous VLC (www.videolan.org/vlc/): it doesn't need any additional codecs and can play virtually anything.

I hope I answered to a few of your questions.
Class dismissed.

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