That depends from the kind of movie (avi, mkv, mpg or 1000 others) you want to show and if you want show it on the PC or on TV.
There are several options on each way.
You must be more concrete.
And at first the subs and the movie must fit together.
If not you must make them fit with a Tool like Subtitle Workshop by sliding, buckling or stretching.
Do you have subs and movie of the same kind, one of the easiest options is to rename the subs
that the name (except the extension of course!
) is exact the same like the movie, put both files in the same folder and watch them with a program like the VLC-Player.
The subs will be displayed automatically.
But as I said, all depends from your choice how you want to watch the movie and what kind of codec and container is the movie.
"I don't believe in God. I just believe in Billy Wilder" - Fernando Trueba