Hi, Do you have directvobsub installed? It is the software that allows windows media player to display the subtitles. I know directvobsub works on windows xp through 7, hopefully it will work on windows 8 for you. If not try a codec pack such as shark007, k-lite, or combined community codec pack "cccp" which are all free. However, I do not recommend codec packs, never install more than one at a time. Link below.
1. First download directvobsub then install it. You can get it as a standalone program or it also comes with most free codec packs. I do not recommend codec packs, try to install the standalone directvobsub.
2. The subtitle file and the video file both have to be in the same folder and have the same name for example: "vacation.srt" for the subtitle, and "vacation.mp4" for the video file. So drag or move them into the same folder and rename them both the same name if they aren't.
http://www.codecs.com/download/directvobsub.htm (You can get directvobsub here. It will work for both windows media player and media player classic.)
You may try media player classic home cinema also as an alternative player. It has directvobsub and most codecs built-in to it already, plus it does work on windows 8.
http://mpc-hc.org/ (Official site of media player classic home cinema. Available in 32-bit or 64-bit and will download from sourceforge.) Very good free player here.
I hope this helps you out. Good luck!