I have XP and i need hptl5 and mme?
What do I do?
Are those part of firefox itself?
Firefox relies on built-in OS support to play media files via the HTML5 media player. On the Windows XP platform you do not have native support for playing MP4 files with the HTML5 media player.
You can try if the solution posted here to add support for playing MP4 files works for you.