Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Lava Lamp Freak

macrumors 68000
Original poster
Jun 1, 2006
1,574
631
Yesterday I installed Windows 7 using the Boot Camp Assistant. I switched back to OSX by holding down option while booting, and a few hours later put the computer to sleep from OSX before going to bed.

This morning when I went into my office, the iMac was on and had a black screen with the text, "No bootable device found." I pushed the power to turn it off and back on, and it successfully booted into Windows. I thought that was weird since the last OS I used was OSX. So, I restarted again and booted into OSX with the option key. Chrome loaded and had an error that it hadn't been closed properly.

Everything is working fine, but it makes me wonder what happened while I was sleeping. My iMac must have turned off and rebooted into Windows, but it didn't see the Windows partition and gave the error. I just went into Startup Disk to make sure that OSX was selected, and I noticed that both OSX and Windows highlighted. I selected OSX, so I'll see after switching to and from Windows again how it affects the startup disk selection.

With this being a new computer, it just makes me paranoid since I have the Fusion drive. My iMac is hooked up to a UPS and I didn't have a power outage for it to turn off.
 
Do you have any external drives connected? If you're set to windows boot, sometimes it will notice that the device plugged in USB1 isn't bootable and throw that error. It may have auto updated and rebooted to encounter this.
 
No external drives were attached.

After doing some digging, I think I figured it out.

During the boot camp process Windows ends up getting set to be the default OS (why I have know idea). When you are running OSX and it goes to sleep, for some reason, it has an issue with Windows being the default. I was able to run OSX and Windows both, without issue, it was only when OSX went to sleep did this issue pop up.

I went in through system preferences and changed OSX as the default OS. I think that took care of it.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.