im running ubuntu desktop 12.04, and well, i have no idea what happened. my computer lost power and died, and when i plugged it in and powered back on it took me to the sign in page and froze. i turned the computer off again and powered back on, this time hitting f2 and going to boot options, and the boot options page is frozen. ive powered up and down and tried a few times, all i get is a frozen boot options screen any ideas?