I have a commercial instructional dvd - produced by a small sewing pattern company - that plays just fine on the dvd player connected to my TV. However, when I try to play it on the external optical drive connected to my laptop, dvd player informs me I have inserted a blank dvd. The drive is fine, it readily plays both cds and dvd - just not this particular one. I know next to nothing about dvd formats, so I'd appreciate a simple explanation. I am contemplating the simplicity of getting rid of the dvd player connected to my tv and streaming all my dvds from my laptop. Obviously, there is something I need to know before I take this action!