I have the Turtle Beach EAR Force X1 headset and Windows XP Professional.  I installed it properly, but only the earphones work.  I check all of the audio settings and NOTHING is muted.  This device is not in my current collection of tech toys--but it sure sounds like a very fine audio device. I have found a site that has tons of videos (how to's and reviews) on the whole series of the Turtle beach line. The ONE i have linked (it is very amateurish) seems to deal with setup issues so hopefully it will assist you. If not there are many others also listed on the site and perhaps the info you need will be contained there.If it is a new purchase you always have access to Turtle Beach and they do seem very commited to customer satisfaction so calling them may get your solution the quickest. goodluck,truenorthwhere is the link?inventech, OOPS! Sometimes the best of intentions can go awry. Here it is. If the one that is directly linked doesn't help scroll down on the right side of the alternative LINKS on the subject as there are many offered. goodluck,truenorth
http://www.youtube.com/watch?v=YB1XotTyYJk&feature=relatedyou have alternate microphone picked or not picked, go into your mixer or sound options go to recording devices and there should be an advanced tab click there and you should see
1. Alterntate Microphone (or something like it)
2. Sound boost
and check/uncheck and try that out