I have borrowed a DVD-R disc from an elderly relation containing a film clip of his father who was a musician (old clip from 1929). However, I can’t read the disc on any of 3 players connected to various computers, or in my DVR. The computers can’t see anything on the disc and actually say that I should insert a disc. I would have said that the disc is a dud, but I have just seen it played on a DVR in the owner's home.
I have downloaded MagicISO, Any Video Converter and CloneDVD and none of them are able to read or detect the format of the DVD.
I know that the owner of the disc had it made by a relative in USA (he and I are in UK) and wonder if there are any differences.