First of all, THANK YOU everyone for answering!
I already did... I could recover some of the pictures, but most of them weren't readable at all or were recovered in mosaic-style, if you know what I'm saying...
The discs weren't mistreated at all... There's no single scratch of any of the DVDs, I put them in a good cd-case, so...
I used some cheap TDK-DVDs...
So, another question:
Would it be better, if I bought a DVD-drive with very good reading ability but without writing ability, or doesn't it make any changes if I buy a normal DVD-burner?
And then, which drive (name of company + product) do you recommend to me?
Again, thanks a lot for your answers!