Make sure the microphone is plugged into the correct jack on the back of the 
card. 

The Mic In on the Montego is the red jack located second from the top, 
not the top jack which manual indicates. 

The correct connections from top down are this:

Blue - Line in
Red - Mic in
Green - Line out

Game Port.

Also, make sure that the microphone is selected in the mixer's record 
section and that it's slider is up.

If you are still having difficulty, make sure that the Montego is selected 
as a record device in Control Panel -> Multimedia -> Audio (Win 95/NT) or 
in Control Panel -> Sound Mapper (Win 3.1x).