I have a video that I want to add a voiceover to, but my microphone's broke and won't record a thing. I have an HP Pavilion Webcam built into my laptop but so far I can only record video and sound in it. Can anyone help me so I can record only sound in it?

If that doesn't work, can somebody tell me how to seperate the sound from the video in something like Camtasia? Whenever I add a sound/video file in, they're both conjoined and I can't remove one without removing the other.

I can't get another microphone until like Christmas and I want to get this video done as soon as possible so if anyone could help that would be great.

Doesn't windows have a sound recording program already built in, just use that for sound.

I need a microphone. If you mean SAM, I'm not using that.

If it's a laptop with a webcam, it probably has a microphone built into it.

Problem is how to access it.
Should I try something like Audacity?

EDIT: Audacity works. Thanks for pointing me in the right direction.

In any program that uses a microphone just go to the settings > usually the audio settings (microphone settings if they have one) > then select your microphone (usually by default).