I am using Audacity 1.3 Beta and it use to work fine until I factory restored my computer. I redownloaded the Audacity program and it didn’t work. My computer mic says its enabled and working, but when I bring it into Audacity I get two blue flat lines.
It’s really hard for us to see over your shoulder, much as we would like to help.
I would try a process of elimination. Try a different mic. Try the same mic recording with Windows Sound Recorder (click the Windows globe and type “sound recorder” (without quotes) in the search box).
In the Windows Control Panel, look in “Sound” and in any separate control panel the sound device has for a mic mute.