There's another post in this forum, the person was able to:
I FIXED IT!! The fix (if you haven't bought a new sound card) is to go to
C:\Program Files\Analog Devices\SoundMAX\ and run ATIrem.exe. This will remove all the soundmax files. Then put in the ASUS cd and run the "Add New Hardware Wizard". It'll find the sound controller and then you just have to reinstall it. Once it's reinstalled go to ctrl panel > sound devices > voice > volume and make sure mic is checked with the volume up. Then click properties, playback, and okay. Click file then advanced properties if it isn't already checked. Then click the advanced button under microphone and make sure mic2 select isn't checked. I checked it first, then unchecked it. VOILA, the mic SHOULD work...THANK YOU! I too have been searching for a fix for the last 8 months.
(I signed up just so I could post this)
My problem is, I have a grayed out Advanced button...I believe you need to select Mic2...my problem is exacerbated by my not having the CD the board came with...and Asus doesn't seem to have it for install. I may just buy a chintzy audio card JUST to be able to use speech on team Fortress 2!