if you are looking to play a video from the internet or a dvd then try VLC.
This is cross platform software ( you can use it on Windows or Apple)
VLC Features Include
“Simple, Powerful and Fast
Plays everything, Files, Discs (DVD, CD, VCD, Blu-Ray), Webcams and Streams
Plays most codecs with no codec packs needed:
MPEG-2, H.264, DivX, MPEG-4, WebM, WMV player
Completely Free, No Spyware, Ads or User Tracking
Works on most platforms: Windows, Linux, Mac OS X, Unix…
Media Converter and Streamer”
Check out the website for the full list.