Bootcamp "No bootable device" message when trying to install Windows from a DVD
Like other people whose postings I've read on several web sites, I too got that aggravating "No bootable device..." error message from my Mac (in this case, a Mac Mini running OS X 10.6) when I tried to install Windows 7 using Bootcamp Assistant. After several hours of troubleshooting on my own, and several more hours of fruitless troubleshooting with a Mac customer support rep, I finally found a solution.
Background:
I purchased my copy of Windows 7 (64 bit) online from the Microsoft store web site. I downloaded it to my Mac as an ISO file. However, to install it using Bootcamp, I had to make a copy of it on DVD. So, after I downloaded it, I right-clicked on the ISO file's image, then selected the "Burn...to disc" option. The Mac then burned the ISO image to a DVD for me. The DVD's contents and the ISO file's contents looked virtually the same when I viewed them in Finder. So, I figured I was ready to go.
I opened Bootcamp Assistant, partitioned my hard drive, inserted the Windows 7 DVD, and selected the "Start Installation" option. The Mac then rebooted and after a moment of seeing a blank gray screen, the screen went black and then displayed that "No bootable device..." error message. No matter what key I pressed, nothing worked.
To cut to the chase, the problem, at least in my case, was that Mac burned my DVD in "Mac OS Extended" format. (I don't recall the Burn utility giving me the option to choose the DVD's format. Apparently, it chooses the Mac OS Extended format for you.) After trying many other things, I discovered that, at least for my machine, the Mac OS does not recognize a DVD in Mac OS Extended format as a bootable device. On a lark, I downloaded the Windows 7 ISO file to an older Windows machine I had, and used a different Burn utility to burn another copy of the DVD. In this case, the utility burned it in "UDF" format.
When I tried the Bootcamp assistant install again, this time with the Windows 7 DVD in UDF format, it worked perfectly!
I'm a newbie to the Mac. Maybe a Mac vet would have known about this situation, but I didn't see it documented anywhere in the Bootcamp Windows Installer printed instructions, nor did I learn it from the Apple customer rep. I'm obviously not the only person out there who has purchased a copy of Windows online, instead of shrink-wrap format, used the Mac disk burning utility to create a DVD version of the ISO file, and then subsequently encountered this "No bootable device" error. I'm absolutely amazed that Apple either doesn't know about this issue at all, or hasn't bothered to let its customers know about it. In any case, I hope this post will spare someone else who encounters this problem several hours of aggravation and unsuccessful troubleshooting.