How do I change the overall default media player in Windows?

I have a Microsoft Digital Media Pro keyboard with a bunch of buttons along the top for shortcuts. I just recently formatted and reloaded windows, due to some driver issues. Before the format, when I pressed the Play/Pause button and no media player was open, Winamp would open and start playing. Now, after the format, when I press the button, Windows Media Player opens. If I already have Winamp open, the buttons control it properly, and everything is peachy. But usually the first thing I do after my computer boots up is to hit the play button to launch my music. In the keyboard settings, I can choose different settings for that key, but it is already set to the correct one. I just want it to launch Winamp if there is no media player open, and work as it currently does after Winamp is launched. I checked Set Program Access and Defaults, but I can only choose WMP or Zune as the default media player, which are both garbage IMO.How do I change the overall default media player in Windows?
I think there is a thing in control panel that says Default Programs, it might be in there or go to Autoplay and change the default for each multimedia item.