Level 1

4 points

How to fix "No bootable device, insert boot disk and press enter" ?

I tried to use Boot Camp Assistant to install Windows 7 to my Mac mini (mid-2011, i5 2.3Ghz, with most updated OS X Yosemite), and the Boot Camp Assistant formatted my USB drive and copied the ISO image of Windows 7 into it successfully. However, when the Mac mini automatically rebooted, it showed the message "No bootable device, insert boot disk and press enter". I tried to switch off the mac mini and hold down the alt/option button when I turned on it again, but no any menu appeared (only the same error message was displayed).

I also did some research on internet and found some experts indicated that the USB drive is using MBR (for old BIOS) rather than GPT, and UEFI only recognizes GPT, so it isn't bootable. Is that exactly the problem? The USB drive was formatted by Boot Camp Assistant actually, why would this happen?

Now I don't know how to fix this problem. I cannot boot into OS X now. Anyone can help?

Mac mini, OS X Yosemite (10.10.3), mid-2011, i5 2.3Ghz

Posted on Jun 13, 2015 10:17 PM

Top-ranking reply

SunnyLau175 Author

Level 1

4 points

Posted on Jun 20, 2015 9:53 PM

Thank you. I have successfully installed Windows 7.

I tried the following steps:

1. bought a new SanDisk Cruzer USB flash drive

2. formatted USB flash drive as Mac OS Extended (Journaled) with GUID Partition Table by using Disk Utility

3. ran Boot Camp Assistant to remove previous BOOTCAMP partition

4. used another Windows PC to make ISO image from my DVD again

5. ran Boot Camp Assistant again to start making USB boot drive, partitioning and installation

(Boot Camp Assistant formatted my USB flash drive again as FAT32 with MBR ......🙂)

6. ran Windows Installer from my USB flash drive successfully when my Mac Mini automatically rebooted

7. used Startup Manager (by pressing Alt/Option on start up) to choose booting from BOOTCAMP partition when the Windows Installer finished an initial installation and auto-restarted my Mac

(I found that I cannot show Startup Manager before because of my KVM. When I plugged my keyboard directly to my Mac Mini without KVM, the Alt/Option button worked again when I pressed it on start up ......🙂)

8. finally installed Boot Camp and the attached drivers manually from my USB flash drive into my Windows 7.

I still had to use Startup Manager to boot into Windows every time until I installed Boot Camp driver.

Thanks very much for your help. I might not be confident to try again without your suggestions and comments.

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19 replies

SunnyLau175 Author

Level 1

4 points

Jun 19, 2015 6:19 AM in response to Loner T

No, only OS X is on my system now.

Bootcamp created a blank FAT32 partition for me to install Windows, but my mac cannot boot from the USB drive.

Loner T

Level 9

59,536 points

Jun 16, 2015 8:02 AM in response to SunnyLau175

1. What type of keyboard connection do you have?

2. Does OSX boot properly?

3. Does Command+Opt+R boot into Internet Recovery? Reference - OS X: About OS X Recovery - Apple Support .

Loner T

Level 9

59,536 points

Jun 14, 2015 7:51 AM in response to SunnyLau175

If you power cycle your Mac and hold the Alt Key, can you boot into OS X?

Loner T

Level 9

59,536 points

Jun 21, 2015 6:17 AM in response to SunnyLau175

Glad to see it all working. Hubs/KVMs cause issues as you found out. Usually BC drivers are silently and automatically installed. They can be repaired using USB2 built by BCA, if necessary.

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How to fix "No bootable device, insert boot disk and press enter" ?