You seem to be trying to download faked files; stay away from files with hundreds of hosts. Choose from files with some 10-20 hosts (though it seems that also some faked files -especially music- appear in between them).
As for your preview problem, go and check whether you have the LW player enabled (but the player will only preview music files; for videos it normally switches to your default media player).
Go LW>Tools>Options>Player
