Welcome to G2G
I'm going to have a shot at this one as no-one else has replied but I warn you now - I'm not a gamer and I never use a microphone so I may not be much help! This is based purely on what I know from setting up mics on other peoples systems on the odd occasion...
1) Right click on the speaker icon in the bottom right corner of your screen & select Open Volume Control
2) You should see a volume control for the mic. Make sure the Mute checkbox is ticked for the mic volume
3) Next click on Options -> Properties. Make sure the correct device is selected in Mixer Device, then select the 'Recording' Radio button. Make sure that all the items listed in the box below it are ticked.
4) Click OK
5) In the Recording Control window - you will either have 'mute' checkboxes for each item or 'Select' checkboxes. If you have Mute boxes, make sure every Mute checkbox is ticked except for the MIC and Mute All boxes.
If you have 'select' checkboxes, then make sure only the MIC box is ticked.
Let me know how you get on
You're say is 1000% times better than my say =p
I got to Options -> Properties part, then, it has two choices..
Soundmax HD
OR
HD Audio front mic - I'll give you a warning, I think I'm using a Motherboard soundcard, as my Soundcard didn't fit in my case =P
For HD Audio Front mic, it says only RECORDING and MICROPHONE is the only tickable subject..
Then I get to Soundmax HD
Rear Input and Stereo Mix, Stereo Mix wasn't ticked, so I ticked it OK> Then I can only tick Rear INPUT or Stereo mix, I can only tick one of the two, I'll play around with them mate, but your expert skillz would be awesome =p
Cheers, and a great start with G2G =]