I boot from a DVD the last version of ubuntu 12.04 x64(because i have 8g. of ram) ,hit install Ubuntu ,check Install Along windwos 7(or something like this ,anyway the first option) and the button in the bottom right corner says "Restart to install" or just restart...i cant remember. So ,i hit the button than ,the screen goes black ,some proceses are stopped and on the middle of the screen it writes like this " Please remove installation media and close the tray (if any) then press ENTER: "

The DVD rom opens and i remove the dvd ,close the tray ,pushing enter and the windows is starting ,no instalation ,no file copied to my PC ,nothing.