Blank screen with blinking cursor.

I have an old Hp G4 from like 2011. I was trying to install Ubuntu and thought it all went great. But when I tried to restart I get the hp logo and at the bottom I can press Esc to get to a settings menu. From here I can only get to the InsydeH20 Setup menu or to a blank screen with a small flashing line or cursor. What did I do wrong? Or more importantly, How do I fix it? I have tried running a disk that has Ubuntu 14.04 and I can hear the cd/dvd running but it remains at the little flashing line at the top left-hand corner. From the options that are given at the set up menu I tried booting from disk and from internal. to no avail. Is there something that I'm doing wrong? are There any secret Commands?