Well, my BIOS UEFI stopped to show up during the boot these last days, I tried the solution of MarbleMuffin unfortunately it didn't work. Actually, the BIOS option didn't show up but the OS Ubuntu did.
Because this change clearly seems to be related to a kernel update, I uninstalled the last kernel as presented in documentation through Synaptics program. The issue now is neither the BIOS, nor the OS show up. But I have a laptop (windows 7 based) where I did launch a flash session of Ubuntu and I can access the PC's hard drive (the root and the home user) connected by a docking. So that's why I wondered if it is possible to repair the OS Ubuntu system of my PC's hard drive through an Ubuntu flash session on my laptop, because I can access all the files.
I don't know if this is crucial but when I ask the laptop to boot on the PC's hard drive peripheral, there is only a white underscore "_" showing up for ever. I don't know if it means the OS system is clearly dead.
