Really stupid Windows 7 mistake?

Okay so I’ve been having problems with the sound in Win7. When I start up, the sound works fine. But sometimes, if I don’t use WMP or youtube or something that makes noise, for an extended period of time, the audio just stops working. So I’ll go to play some music or watch a video and it will be playing, but no sound. The only way around this, I’ve found, has been to restart.

So the other day I was looking around in the device manager, and there was a drop down menu for my speakers that said “Enable this device” and “Disable this device.” Now obviously they were already enabled, so I select disable.

Well, it worked. Now I can’t re-enable them. When I go to Hardware & Sound and try to find new devices, there’s nothing there. It doesn’t find anything whatsoever.

If someone could PLEASE tell me how to get this at least back to how it was before I decided to start clicking buttons, I would be much appreciative.