Normally if you tried to open a .wmv it would say something like "Format not supported". But after you've installed this you can now play those formats that are otherwise not supported by mac.
After you've installed it you don't have to do anything else, you just double click a .wmv or something and QuickTime Player will open up and play it.
Yeah soon as the forum picks up then I might be a tiny bit less active. Tomorrow I'm getting reach (if they have my copy still), so I'll need to do my HW right when I get home, so I don't end up like this at 11:40 on the forums.