Getting the DVR material onto your computer is a bit more complicated than you think. The files are not accessible directly (that I am aware of anyway).
However, I have a small desktop computer that is part of my home network that spools movies to the TV using a VGA -> HDMI interface. I also download DVR material to that computer using a Haupauge Streaming video HD capture device
HD PVR Product Description
The downside is the capture is in real time and so the capture takes as long as the show takes to play. Once captured, you can edit as required to remove commercials and remove leading material and trailing material to just save the TV show/movie.
For movies; Netflix is better as there is no editing required.