Plays on the DVD player but not the PC.
Most likely a CODEC issue. CODEC ='s compression/decompression schema.
You need to figure out which CODEC the DVD burner used and make sure you have the same or compatable on your PC.
For a general CODEC that supports most DVD try Divx,
http://www.divx.com/
Or put the DVD in, if your PC recognizes it as media and allows you to open and view the files then you can use something like mpeg streamclip,
http://www.squared5.com/ to demux the file into something that you can deal with.
On the DVD you will be looking in the VIDEO_TS folder for the .VOB file.
Scott