I wanted to install Ubuntu Desktop 12.04.2 LTS on a 64-bit computer. I downloaded the ISO files using BitTorrent and created a USB flash drive installer. On booting from this USB flash drive, I got this error:
/casper/vmlinuz: file not found
The fix turns out to be simple. Remove the USB flash drive, reboot back to Windows and plug it back in. In the casper directory of the flash drive, there is a file vmlinuz.efi. Remove its extension to rename it to vmlinuz. Try the installation again, it should work.
Tried with: Ubuntu Desktop 12.04.2 LTS