I updated from XP sp3 to Win7 home premium. ITunes always sound fine and some movies play okay but most sound muffled or boomy. I have acreative SB X-fi unit. I got the latest drivers. I installed a codec pack but it may not be the right ones loading. Any ideas? If there is a way to find out what codec is being used or 'asked' for then I may be able to find a commonality and go from there. BTW this happens for various movie extensions ranging from FLV to AVI to MPG so it isn't that.

This might sound funny but I had a client once with a similar problem and found that moving the sound card to a different PCI slot sorted out the problem. Try this if ALL else fails...


Hope this helps...
Cheers
Grant

Did you do a clean instll of Win 7. Its not recommended to do an upgrade installation.

You have to do a clean install since you can't go from XP to 7 as an in place install. I did use laplink to migrate the applications afterwards.