You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

External Boot Camp SSD not showing up in Startup Manager or Startup Disk, and cannot access from recovery mode

I'm installing Windows on an external drive (Samsung T5) since my computer doesn't have terribly much room for a full Windows install with my productivity and gaming suite. I followed the instructions here, and it did all the right things, except for right now - it doesn't display the startup disk in Startup Disk under System Preferences, or in Startup Manager with the alt + Restart. It was visible in Recovery Mode, however it said "The bless tool was unable to set the current disk". I've changed the security settings in Startup Security Utility to the "all signed utilities" (medium setting) and also allowing external disks, so it should work - but it's just not showing up. What are some steps I can take to troubleshoot this? (I've checked the drive is formatted as NTFS after the Windows install, and all the program files are there - the computer's just not recognising it.)


All details are below - more than happy to provide more information. Thank you in advance for your help.


System info:

macOS Catalina 10.15.5

MacBook Pro 16"

Windows 10 64-bit Education Edition

MacBook Pro 16″, macOS 10.15

Posted on Jul 8, 2020 7:14 PM

Reply
Question marked as Top-ranking reply

Posted on Jul 12, 2020 4:15 PM

Hi Loner T,


Thanks for that - I managed to fix it using a newer guide on Medium (link) - basically, what the older guide didn't mention was that you need to format the external drive as a GUID Partition, rather than a Master Boot Record. I did this, and everything else worked.


Thanks for your reply though!

Similar questions

5 replies

External Boot Camp SSD not showing up in Startup Manager or Startup Disk, and cannot access from recovery mode

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.