I am affected by this bug as well. I have a Windows system on internal drive and installed Ubuntu on an external drive. GRUB installs to the internal drive even if I chose the external drive. Here is what I did:
1. Boot Ubuntu from my bootable USB drive used for installing the system.
2. Download a tool called boot-repair. Use it to install GRUB to my external drive.
3. Remove the GRUB in the wrong location by following the top answer [here](https://askubuntu.com/questions/429610/uninstall-grub-and-use-windows-bootloader). Alternatively, mount the partition mentioned in the link using the Disks app in Ubuntu and remove the GRUB files for Ubuntu in the wrong location.
4. In the BIOS, remove the option in boot menu that no longer works.
This bug is fixed in the 24.04 installer, but 24.04 did not work for me. You can prevent it by disconnecting your irrelevant drives before installing. Some BIOS allows you to disconnect them, if it does not, do it by physically pulling out the drives.
Edit: By 24.04 did not work for me I mean some other bugs happened that made me stop using 24.04.
I am affected by this bug as well. I have a Windows system on internal drive and installed Ubuntu on an external drive. GRUB installs to the internal drive even if I chose the external drive. Here is what I did:
1. Boot Ubuntu from my bootable USB drive used for installing the system. /askubuntu. com/questions/ 429610/ uninstall- grub-and- use-windows- bootloader). Alternatively, mount the partition mentioned in the link using the Disks app in Ubuntu and remove the GRUB files for Ubuntu in the wrong location.
2. Download a tool called boot-repair. Use it to install GRUB to my external drive.
3. Remove the GRUB in the wrong location by following the top answer [here](https:/
4. In the BIOS, remove the option in boot menu that no longer works.
This bug is fixed in the 24.04 installer, but 24.04 did not work for me. You can prevent it by disconnecting your irrelevant drives before installing. Some BIOS allows you to disconnect them, if it does not, do it by physically pulling out the drives.
Edit: By 24.04 did not work for me I mean some other bugs happened that made me stop using 24.04.