MDF and MDS files are CD or DVD images file. You will need to use special program to open and burn them. Below are a few programs that can open mdf and mds files.

– MagicISO (Freeware) http://www.magiciso.com/
– Alcohol 120 (Trialware) http://www.alcohol-soft.com/
– Daemon Tools (Freeware) http://www.daemon-tools.cc/dtcc/download.php

You can use the above programs to create a virtual drive and then mount to your mdf/mds folder to load the image. This way you don’t need to burn them to CD/DVD to watch and can watch them on your PC.

We found that MagicISO MagicDisc is the best for mounting virtual drives.

– MagicDisc Virtual Drive http://www.magicdisc.net/setup_magicdisc.exe