Help with mdf files

I am having problems with mdf and mds files, the problem is that i can not file suitable program to unpack these formats, i have tryed everything, but nothing works.:sad:
Can you please recommend me a program and just in a few lines how unpack images.

I have tryed (daemon tolls, Alcohol 120%, Iso buster, Magic ISO, Ultra ISO, CloneDVD) and probably a couple of them more buti can not remember.
:disagree:

How did you create those files?

I did not create them, some guy from newsgroups send me comics, and the funny thing is that all the other people who get the same comics, managed to open them and I was the only one with a problem, the send me their procedure of opening the file, but it does not work, normally it works for other people.

In this case take a look at this awesome website with a step by step tutorial.

[B]The Ultimate Newsgroups Unpacking Guide[/B] *sponsored by philamber