i have (had) a dual boot ubuntu-Win8 on UEFI and i also have Mageia on another partition. Everything was working fine, Grub was able to run Ubuntu - Win 8 and Mageia without problem but after a BIOS reset to default settings Grub seems gone and on startup i only have Mageia boot loader (this load fine) but _Ubuntu is gone and Win8 doesn't load.
I've used a LiveUSB of secureUBuntu and run boot repair few times with no luck
my bios now is set with Boot mode as LEgacy Support and Boot priority as Legacy First
Changing to Boot mode as LEgacy Support and Boot priority as UEFI first doesn't help
here last boot repair