im running ubuntu 12.04 and it refuses to boot up. the screen will come on for a second, the mosue will appear, then itll go black again all inside about 3 seconds. i let it just do that for a while and eventually a window popped up saying i had a display issue. I didn't have a mouse but there was a button saying "ok" at the bottom that i couldnt click on. i hit enter, got through that screen, now im looking at another that says "What would you like to do?" - run in low-graphics mode for just one session - reconfigure graphics - troubleshoot the error - exit to console login

then two buttons, cancel, and ok. I dont have a mouse and its not letting me navigate between these options with tab.

firstly, if i make it through these windows will it get me into the computer so i can try and fix whats going on? also, whats going on here? also, how can i click on these buttons without the use of tab or a mouse?