Today I accidentally disabled my Windows 7 laptop speakers. I was installing Skype and testing it with headphones. I was getting the voice from other side from the laptop speakers, not through headphones. So I went to Control Panel–> Sound and disabled the speakers. So now only headphones were enabled, so the voice started coming through headphones. But now how to enable the speakers back? Now in Control Panel–> Sound, I was not getting speakers anywhere, so there was no way to enable them. Then when I googled it and found this article.
The solution was simple. In Control Panel–> Sound, in Playlist tab, Right Click and check Show Disabled Devices. Then select the disabled device, speakers in this case, go to Properties and there you can enable them. Hope this helps.
Happy Listening !