Ive recently upgraded to 13.10 and its just not for me, so what i want to do is downgrade back to 12.04(which i know works perfect for me). I downloaded my 12.04 amd iso but alas, it wont let me pick my iso file, usually the iso is already set, as a matter of fact. It just shows an empty bar. Im not sure what to do. Semi-novice.