TL;DR: I installed Android x86 on USB with main HDD detached. Now whenever I want to use that Android on USB, I have to detach HDD, else USB doesn't boot & says
This is not a bootable device. I want to use Android while main HDD is still connected. Thanks.
I installed Android x86 (LineageOS) on a USB flash drive, but before doing that, I had manually removed the computer's main Hard Drive. The USB drive was the only drive attached to the PC then (other than empty CD drive). Installation of Android worked OK, everything worked great, Android operated fine, etc. Then I reverted my system back to normal state, by removing the Android USB, and replaced my original HDD in the system, which now operates as normal with original OS in it (Windows).
Now the issue is that if I want to use Android again via that USB, it will only boot if that USB is the only one attached to the PC. That means I have to manually remove the HDD every time. If I keep the HDD in and boot the machine via USB (computer's boot device chooser menu via F12) there's an error
This is not a bootable device.
So I would like to use Android in that USB while the main HDD is still attached. How should I do that (without having to reinstall Android LineageOS elsewhere as I have things stored in it and I have spent quite some time tweaking many settings and customizations etc)
Additional info (if useful): When I read the Android USB in Windows, it shows up as a drive labelled 'EFI' which has the following in the root:
\boot \efi \LOST.DIR \Android BOOTEX.LOG startup.nsh
Thank you very much.