Microphone wont work.

[Hunders]

I recently built a pc for my little sister and I am having problems with the microphone not working. At first I thought it might be a dud mic so I tested it on my PC and it worked fine. Then I thought that maybe the onboard sound was causing the problem so I bought an Audigy 2 but the problem still persists

Does anyone have any ideas on what I could try to get the damn thing to work?

Thanks.

 

[200sx]

enable +20db boost in the windows volume control?