I plugged in a microphone ant tried recording my voice as a test but it didn't record. Why not? I tried it with the mute button on the microphone in both positions, as I don't know which is on or off.
This is windows XP, although I get the same results in Windows 7

Hi Stephen

Open up sound recording via Start/Accessories/entertainment/Sound Recording
In Sound select edit/audio properties.
Is Sound recording device the same as your Sound playback device.
If not using the drop down menu select it from the list

Jim

there can be a problem with ur mic