Audio Codec I Cannot Play Movies Back On My Windows Media Player That I Copied To My Pc. Says Im Missing A Ac3 Audio Codec?

I cannot play movies back on my windows media player that i copied to my pc. says im missing a ac3 audio codec? - audio codec

If I am the Web using, say, the search is to download, but you do not know what I'm supossed to download, says nothing AC3 audio codec. Everything I have seen many things AC3Filter. I do not know what I'm supossed download A. They all have a different number.