Hi and thanks for all your efforts ! I tried an USB-stick with OSX Mountain Lion made with Unibeast Firstly with no options in bootloader it gets into trouble with the graphics card it might seem, since it stops right after exiting the bootloader. Then with "GraphicsEnabler=No" it gets further, but stops at "Still waiting for root device", is this because of the USB 3.0 ports ? The machine does not have any USB 2.0 ports at all. What are my options, should I try to make a bootable DVD ? Can anybody help me with this issue ? Dell Inspiron 17R SE 7720 CPU : Intel Core i7 3610QM Memory : 6144MB (1x2048 + 1x4096) 1600MHz DDR3 HDD : 750GB 7200 sATA Graphics : nVidia GeForce GT 650M 2GB & Intel HD4000 i believe Screen : 17.3" 1920x1080 Wireless : Intel 2230 WLAN card (802.11 + BT 4.0) combo USB : 4 USB 3.0 Ports Ole A.