to DJMORBID and anyone else still struggling with mkv. Ive done it!!!! Nobody in the forum mentioned about the Matroska pack being a vital part of the conversion process. I found by accident elsewhere that someone had managed to convert mkv to mpeg using TmpGenc. So this is what you need go to http://ld-anime-faireal.net/guide/matroska-en you can read a bit about it but within that site you go to http://packs.matroska.org Download Pack Full v 1.0.2 When you run TmpGenc and open H Potter or whatever your mkv is, it will open up (at long last thank god) then just carry on to the end clicking the various boxes to get to next page and of course ensure you have compressed it to under 4070 GB, then hit the okay button or whatever it is, and it will start encoding. The bad news is that it takes around 5 hours (bearing in mind this particular film is around 2 hours 15 mins long) so I went to bed and left it "cooking", this morning, I opened up TmpGenc DVD author ran the file through, another 30 minutes, then used their burning program which is a bit slow but onto a dvd+RW, another 30 mins - I usually use vso's CopytoDVD, much quicker, but I wasnt expecting any great shakes, so went along with the existing program. So I have quite a reasonable copy on DVD, one slight disadvantage, the sound is not that loud, also some of the scenes are a little yellowy at times but all in all acceptable. However, I would not bother with mkv again and as the guy was pretty clever who actually produced it and evidently had a dvdrip, it could have been converted into avi which would have been better quality and I would have used Direct from Divx2dvd, which would have taken, considering the length of the film, around 75 minutes on a dvd rw for the whole process. Anyway, thanks to Shiroh and all for your help and I hope this post will help others.