Is this a laptop or a desktop? There seems to be a 3070 desktop with win 7 drivers, and a laptop without. Is the issue happening with all play-back? Movies, music, streaming video, DVDs?
If sound is the only issue with speed (video play OK, erc..) it's probably just the fact that you have no or the wrong drivers for it.
You can try Vista drivers (if those are available) or extract the Vista or XP driver files from the download and point Windows directly to the files needed, but that may not work.