You need to give some specifics if you expect help.
If it's related to watching something online, you need the latest Flash player version. Maybe some codecs too. If it's something else you need, listen to my neighbour from upstairs
add the following as required k-lite codec pack from free-codecs.com - use classic player quicktime flashplayer shockwave try installing xbmc if it is local stuff, if your pc is powerful enough, it'll most likely play it for you as well