This can be due to multiple reasons, just make sure that Elive is correctly installed, I can also suggest to use the automated partitioning mode, which will remove all your disk contents but should take the best choices for your system.

If you still cannot boot your computer then you may have a very bad BIOS, I have seen this before and it is the reason that there was added (since the version 2.4.6) a special option in the booting of the live-mode of Elive which allows you to boot from your hard disks (from the Advanced menu of the first Boot on Live mode)

Notes about my specific experience: In my personal case seems like the bios thinks that the main disk is the secondary disk, but there’s no secondary disk at all and so the bios (the computer itself) is simply unable to start booting the disk, so using those options I just need to select “boot from my secondary disk” and it is able to boot correctly, it is of course not the best way to do it but at least this computer is able to work, suspension instead of shutdown can help too. In any case I’m 90% convinced that if he reset the bios (loading default settings didn’t worked) could make the bios read again the correct identifiers of the disks and work back, but to open the entire computer and search for the switch requires time, maybe upgrading the bios can help too, if there’s any update at all.