Lightning - Many thanks. Tried using Isopuzzle 1.7 but couldn't read anything from the disk - don't know if makes any difference but I'm not sure the WNASPI32.DLL I was using was the latest (or correct one for Win 8.1). I couldn't find the one suggested in Isopuzzle readme file at Nero.com. Anyways, I finally got Isopuzzle to run and scan the entire disk but it wasn't able to read data from any sector. Seems a bit strange cos Imgburn managed 44% read of good sectors before giving up.
Looks like I may have lost all my photos