I am installing on a HP SLIMLINE PC s3200n, internal sata HD and External USB drive. Installing to external drive, which is recognized as SCSI4. I chose to install grub to this drive, also because I didn't want to mess with my Vista drive at all, I will just choose to boot from this drive at startup since HP has a screen asking for which boot device at startup. Anyway, it will install to SCSI4 but I get a grub error, won't load at end of install.
After reboot, I choose this drive and grub error 18, I believe.
Is there a solution I can use to boot from my external USB drive?
Ubuntu has same issue.