The format of a dvd must be UDF, otherwise it'll only play on your computer! I've never dwnlded a 'so-called' dvd. But I have dwnlded some movies. A true dvd is in mpeg2 format. But I notice many offered are only mpeg1 (vcd format) or something else like divx, etc. All mpeg formats are what's known as 'lossy' compressed formats. ie: they throw away info to help them compress. If a mpeg2 movie has been converted to another format & even converted back to mpeg2 for distribution, it'll mean it's been compressed twice with large amounts of movie info thrown away. So if you do manage to burn these files you have, don't be surprised if you notice a loss of quality. But then, there's other techniques such as extracting the dvd's files & reducing them just enough in size to fit onto a dvd5 format disk (4.7GB.) If yours is around 4.4 GB in size, you know that you should at least have reasonable quality (depending on the app that did the job - some are better than others!) Most commercial dvd's use the dvd9 format & range in size from 6 to 8 GB. So if your movie is less than 1 GB in size, don't expect it to have magically great quality!