Hi,
Try this, Control panel
open the volume controls
click the options menu and then check advanced controls
click the advanced button under microphone
check off Microphone boost
mic boost should always be in advanced mic options
something else, control panel , sounds and audio devices
if you have category view it will be under: sounds, speech, and audio devices
go to the voice tab and click: Test Hardware
check sound recording tab,advanced, microphone select properties
these are all the microphone settings that I know of that may fix your problem
Cheers