Hi there
1) from the LIVE CD boot normally - a non UEFI system won't offer the UEFI version.
2) on install choose the target HDD carefully -- choose custom as in the link shown below.
Here's a post on a WINDOWS Forum about installing OPENSUSE on a totally separate HDD and booting from it. The post was in how to create a portable Windows system -- however you can ignore the sections on installing VMWARE and a Windows virtual machine. Just follow the LINUX steps. (Although the title is in creating a Portable Windows system the first steps explain how to create a bootable OPENSUSE system on the external HDD before adding the windows system).
If you WANT to add a Windows system --works fine too -- vmplayer is 100% FREE.
http://www.eightforums.com/installat...y-version.html
Pay particular attention to steps 5 and 6. !!!
(I suspect that at upgrade time the GRUB BOOTLOADER got hosed up or installed with the wrong options -- IMO it's far better installing 13.1 from scratch --it's going to be a Long Term support version so it's worth getting it right. Upgrades also particularly where the kernel is involved can result in some applications not working properly as well).
cheers