A few days ago I began a bootcamp installation but then changed my mind half way through. Using disk utility I restored my drive back to one partition and forgot about it, and I only ever put my Mac to sleep and rarely shut it down. Anyway the other day we had a power cut and my iMac had restarted itself through the night. I awoke to find it sitting at a black DOS style screen saying 'No Bootable Media Present' which is typical of a Windows Installation gone wrong. Anyway I restarted the machine again just to make sure it wasn't a one off and yet the same thing happens again which means I have to force restart and boot with the alt key which is rather annoying. So far I've tried the following as remedies: - Ran disk repair in Disk Utility. - Triple checked that I only have one partition with Disk Utility and GParted Live CD. - Checked startup disk in System prefs to make sure there is only a 10.9 option...which there is. So now I'm stumped. Something from that aborted Bootcamp installation has remained. For the record, I didn't actually finish the bootcamp installation on a restart. It got as far as partitioning the drive and then I cancelled it just before reboot. Any ideas? I really don't want to have to go through a OS reinstall if possible as this installation was only cleanly put in a week ago.