I installed Windows8.1(VL) on my Imac a few days back and since then i have been getting this issue of no sound. There is this red cross on the sound icon at the bottom right. I have installed all the drivers(Well There is Only One-Realtek HD Audio) and after that also there is no sound. Whenever I troubleshoot it, It shows No Issues detected(It cannot find one). Please suggest me the right way to fix this problem, I have been missing all those great sound qualities in a game of FIFA or Bioshock Infinite. I installed Windows8.1 pro by mistake on the full harddrive, I mean i removed the Mac OSX fully by mistake and now there is just Windows on My Imac!!! Please help me resolve this issue as soon as possible!!