Ubuntu :: Cannot Boot - Grub Kernel Selection Displayed - Freeze After 3 Sec

I locked the screen, came back, typed the password, screen remained black, though cursor was visible and moving. Nothing I could do to rejuvenate the screen. Had to switch to tty6, sudo shutdown -r now. Then, on reboot obtained kernel selection, it proceeded to displaying kernel messages, but froze on sdb, after 3 secs. I figured it was the usb, so turned off, removed usb cables to external hard drives, but again it froze saying something about firewire mouse, the mouse is also usb. I tried several times, but no matter what kernel I chose, I couldn't get it to boot. So I loaded puppy live cd, but now it can't access some parts of the disk. I was running utorrent and the folder with partially downloaded files can be accessed but there's nothing there (there was), and some folders can't be accessed at all.