I have a Sony laptop (VPCEH25EN) and i am trying to install Ubuntu 12.04 LTS. I downloaded the iso named "ubuntu-12.04-desktop-amd64.iso". For installing i created a bootable USB using UltraISO.

When i booted the USB it hangs and shows " Booting from USB ", I even left it for hours and it didn't moved a bit. When I booted the ISO in Virtual Box, it ran well.

I even used other tools to make a bootable USB, then it says " BOOTMNGR missing ".

Please help, I am new to Ubuntu and my optical drive is fried.

Thanks in advance..