okay, you'll need to download the drivers/software for the camara (aren't they connected, mic and camara?)
is it only a particular application that you can't record your voice on, or does everything not work?
type, "Set up a microphone" into Windows search and you could try your hand at the wizard that pops up.

Look up your microphone and see if there are any settings you can play with. Here is mine (mic and camara)
Go into your sound and check recording devices and see if the bar moves when you make noise:
Let me know how it goes and I'll help you further depending on what you tell me