5.1 surround sound

:unsure: Hi all hope someone can help me I have 5.1 surrounds,when i Download Music or Films with 5.1 surround can not get them to work only get a hissing noise is there somthing i need to download to rectify this problem.Please Help.Thanx in advance.

Do you hear any audio at all or only the hissing noise???

What media player are you using?

Have you ever installed any codecs that will play ac3 (im assuming the audio codec used was ac3)

what kind of container are these video files in (avi, mkv, or ogg)

Have you made sure that everything is set up right in Windows volume control?

Have you made sure that everything is set up right in Control Panel–>Sound and Audio Devices?

What sound card do you have? What is your computer hooked up to your audio system through?

Installed multi-pack codec everyone you need (kcm)?? onlgetting hissing sound on audio cd’s.Picture great on DVD’s but no sound just a hissing scratchy sound.I’m new to all this but willing 2 learn thanxs again in advance for your help.

type of audio is Realtek ac97 audio