Help!!! how to open .mdf n .mds files?

Cchen

after dowload games, how to open it's .mdf n .mds files?  q$ D# {" L; B$ l% m
i cant open it?
3 x2 L. A1 `( \: Z; [tvboxnow.compls teach me...
9 n0 i1 t  W, A. V8 {tvb now,tvbnow,bttvbtq...