DVD reformat?
 

We have a DVD that a friend made from VHS tapes in his DVD machine.
It will not play in ours, what could the problem be...it plays in his!!
(these are both USA machines if that matters)

What's a DVD machine? What does it do when you try to play? What brand and model DVD players do you two have? It could be making region locked DVD's for a region that his player is (some US players are region-free) and your player isn't, or possibly your or his lens isn't quite in proper alignment (or the lens on his "DVD machine" isn't) and his player is more fault-tolerant than yours. Will it work if you put it in a computer?