made a flash-able USB-Stick with Ubuntu 13.04 on it. When I try to boot without installation or when I try to install it, I get into the GNU-GRUB menu, but not into the normal Ubuntu menu. If I choose one of those I get a black screen. After waiting for 30 minutes I've shut down my PC. I tried it several times, re-downloaded Ubuntu but nothing helps. I've read about the nomodeset option, but I don't even have those menu. If it helps: I have an Asus N56VZ (Notebook) with Windows 8, Intel i7 3630qm, a nVidia Geforce GT650m, 8gb RAM and a partitioned HDD, on which both partitions have more than 100GB of free memory. And the fastboot mode of Windows 8 is also disabled. Please help me, thanks in advance.