That is the weirdest problem I've ever heard.
If it happens on multiple players (Windows Media Player, Youtube.com, RealPlayer, etc.) then it's probably not settings in a program. I know of no Windows settings that will change the speed of ALL media, no matter which player.
My guess is rather than a driver, you're looking at some sort of codec problem. (A codec helps your computer translate various audio and video formats to play in whatever player you use.) Usually, no one sees codecs, as they just work. When they mess up, however, they can cause weird issues. I'd start out by going to
Ninite Easy PC Setup - Silent Unattended Install Multiple Programs At Once, scrolling until you see the K-Lite Codecs. (They'll be under the Media heading.) Check that, and click "Get Installer". Run the installer. This will install (hopefully reinstall) the most common codecs on your computer. (It will also install Media Player Classic, which is a great lightweight (read: fast) media player.) See if that does the trick.
The reason I hesitate to ascribe your problems to a driver is there's not just one driver involved. Your sound card driver runs the sound, but it sounded like everything was sped up, video included. That would mean the video driver is also involved. If you have a common manufacturer like Dell or HP, you can usually go to their sites, enter your Service Tag or Serial Number, and get all the drivers that came on your system. Then you can update them all (one at a time.) That would fix any driver problems.
If you ARE just having problems with the sound, and not the video, then you could go to your PC manufacturer's site and download just the driver for your sound card. See if that takes care of the problem. If you have a Dell or HP, go to their site. If you have another PC Manufacturer, you can try their site, like eMachines, or Systemax. If you have a homebuilt machine, you'll need to know the mfg. of your soundcard, and go to that site.
However, I suspect it's a codec problem, and not a driver. I could be wrong.
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For those wondering about ninite.com, it's just an aggregation of many programs with an unattended installer. Essentially, you tell it what programs on the list you want installed, it downloads and installs them all for you. You don't even have to click Next or Finished for each program. It's a really handy, time-saving method for installing common software.