So I was playing around a bit some time ago with Boot Camp on my new Macbook Pro. I was planning on Dual booting with winows, so had heard of Boot camp and gave it a try. I went through the guide, and resized my harddrive. But before actually starting the Windows installation, I changed my mind. (Using virtualbox instead). I rebooted back into OS X and launched Boot Camp to restore Harddrive again. So far everything is good. I mostly use sleep so did not notice until I had to reboot some days later. Now my Mac starts up it hangs for a while and then I get a black screen with white text that says, No bootable device -- insert boot disk and press a key. Pressing a key will not boot it. Only option is to hold Power button for 5 sec to turn off computer. After scouting a bit I found that Holding the Option(alt) key when turning on PC, or rebooting I get to choose internal harddrive as a boot option. Using that method I can start up the Mac. I tried to run the disk repair utilities included, but they all come out with no problems detected. Anyone have a good idea what has happened here, and how I can fix it?