Hello, I do not very well speak English, but I have install Yosemite 10.10.2 on my AlienWare x51 r2 with this guide. http://www.rampagedev.com/?page_id=144 - Haswell.dmg I do not still have solved the problem of the sound. Wifi and Blutooth, Do not work ! Y bay USB Blutooth and work perfect whit Apple Keyboard and trackpad. Network is unstable Good Luck !