I recently have installed Windows 8.1 Pro. The problem is I connected my speakers at the back jack and they are not working no sound is coming out of them but in windows 7 they worked fine. I checked the speakers with my mp3 player and they are working fine. In the taskbar there is no red cross over the speakers so that shows that I have speakers connected and If i play song the green slider go up and down showing that sound is coming but no sound in speakers. Hope you guys help soon.