it is not cleanly supported as of yet....i know people have gotten the microphone to work to the point that they talk into it and it shows they are talking (with that little icon that lights up when you use your
mic) but no one else can hear you....
i know this problem existed up to winex preview release 1, so maybe since then, there may have been more development in winex for this issue at hand....
so basically your going to have to have winex, and if you wanna test it and see if you can get it going, as its disabled by default cause of the fact that its not cleanly supported..so in your winex config file you will have to search for the line that says:
FullDuplex and set it to "Y" to enable the voice chat, and if you start to experience sound problems, you'll know what the problem is and you'll have to set this back to "N"...
also of course you'll have to make sure its enabled in your cstrike config file also..
so thats the most educated explanation i can give you, so good luck !