Tried everything, install won't work if it installs at all

[tzwcfq]

@SteveC

I can only guess that it’s sda as it never booted off that drive in the first place…

You can check if it’s the right drive/partition with this command:
fdisk -l
If you don’t see your SSD in terminal from Qubes installer ISO then try the SystemRescue ISO.

@SteveC

Anyhow, besides that, if I have to go through what you just described every time I switch OSes…I’ll have to decide if it’s worth the trouble.

It’s not about switching OSes but about removing the drive from your PC.
At the link in my first post there is a fix to this problem:

@51lieal

If you use qubes os as external device, folow this (I assume that your device is /dev/sda and efi partition is 1) :

cp /boot/efi/EFI/qubes/* /boot/efi/EFI/BOOT
mv /boot/efi/EFI/BOOT/grubx64.efi /boot/efi/EFI/BOOT/bootx64.efi
mv /boot/efi/EFI/BOOT/grub.cfg /boot/efi/EFI/BOOT/boox64.cfg
efibootmgr -v -c -u -L MichaelB -l /EFI/BOOT/bootx.64efi -d /dev/sda -p 1