after enable hyper-v on windows server 2008 R2, the audio became choppy, similar issue posted below
http://serverfault.com/questions/172256/vostro-3700-laptop-ws-2008-r2- hyper-v-kills-sound
http://social.technet.microsoft.com/Forums/windows/en-US/9aad0ffe-9332-4f70-b2cb-90c6dffe89e2/microphone-dont-work-after-install-hyperv
