Do you still have no Mic listed after 3.? Then what the hell you're still doing here - you're screwed already! Otherwise, you might be the lucky one. If you have no idea which one is supposed to be correct, you may try to pick up just one after another. You shall be able to turn them back on if you follow step 3. You disable them by right clicking on each and then choose something like Disable from context menu. don't pick up external when you're trying to run integrated and so on) and disable all others.

c) There are more than one device - I would recommend you to try to pick one you believe is correct in your case (e.g.

b) There is exactly one device - just go to 4.

For external one, try to use another if you can or test it elsewhere. If that's an integrated one, try to get drivers or consider reinstalling drivers. you don't have your Mix properly installed and/or recognized.

a) There is still nothing listed, i.e.

Now you shall have listed all devices recognized as Mics. In both cases: right click in the empty area, from context menu make sure that both options are ticked (show disabled, switched off devices - or something like that). Either there is listed something or there's nothing. Go to Start->control pannels->manage audio devices (or sounds.)->recording Either connect your Mic to appropriate jack (don't mismatch with output jack for earphones etc.), or if you have integrated one, go to 2. Other who had the same issue solve it by doing this:

Headset mic not picking up sound