I fool around with Tumbleweed, Leap 42.2 and Neon. Of all the recent distros I have tried, I like Neon the best. However, I have not been able to make another bootable drive as odd as that sounds. I have a working Neon drive which I use as my daily driver. However, when I go to make a second "spare" drive in case of emergencies, I can't. I can easily make spare drives of other distros from USB thumb drives, but I seem to fail on this. USING A BRAND NEW 500 gig SSD, I make a "bootable" drive as normal. It all functions normally until I change drives. When I go back to the spare Neon, the BIOS sees it, but won't boot to it. I tried another brand new drive, same thing happens. I tried an older 250 gig drive, wiped clean, same thing happens. When I switch out TW, Leap or Ubuntu, everything works fine, the BIOS sees it and boots to it. I have tried a couple of older ISOs of Neon and the same thing happens. But I have one good drive of Neon that is fine, but can't make another. What gives? It's a mystery. Any help?????

I have not been able to do this either without breaking my actual computer. If you need another HDD, use Fedora!

I have not been able to do this either without breaking my actual computer. If you need an external boot drive, use anything based on Fedora. That works every time for me; anything based on Ubuntu fails.
Maybe, just maybe, KDE neon Developer Edition will work, as it uses a different installer.. I haven't tried it because Bodhi Linux and KDE neon User edition both failed for me.

louparker wrote:When I switch out TW, Leap or Ubuntu, everything works fine, the BIOS sees it and boots to it. I have tried a couple of older ISOs of Neon and the same thing happens. But I have one good drive of Neon that is fine, but can't make another. What gives? It's a mystery. Any help?????

If I understand you right, this sounds like it might be an issue with the installer in the Neon Live CD/USB. You should be able to configure several drives with different OS's and swap the physical drives rebooting between them without issue. I have no need for this so I haven't done it, but maybe do a clean install of Neon on 2 different drives, one at a time, swapping one out for the other. The computer should detect and boot from either drive one at a time.