UltraIso IMHO is rubbish - it is fine for copying ISO images to your HDD but useless for burning those images to a CD/DVD (For me, at least...). Use Alcohol 120% at the slowest possible burn speed - thats worked fine for me for 2 years. Make sure that both of your mdf & mds files are in a unique folder on your PC. Open Alcohol & select that folder under "Image Burn". Initially you will only see the mdf file displayed - which may cause you concern - but Alcohol will automatically burn both the mdf & mds files to a CD-R & "Presto" - you have a useable V28 CD.....