I recently tried to install a Windows 7 64 Bit Version on my Mac Book Pro Retina 15" via Boot camp. Everything went well but after Windows installation had to reboot the computer all I saw was a blinking cursor. I have been thru lots of forums and hours but I could not fix it. I'm really desperated so I hope some can help me. I also tried to the 'repair your computer' or restarted a million times with out any success. Does maybe anyone know how to enter the Command window because there are some commands to shorten the boot time. I read that the problem is exactly the boot time. But I could not fix it at all!! Thanks for your help!