This question already has an answer here:
I downloaded Ubuntu 11.10 32bit and put it in on USB drive using Universal USB Installer from http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/ .
I then restarted my laptop. I pressed Esc and chose "Boot Management", but there was no option for booting from USB. The only options I could see were boot from hard drive and boot from internal CD/DVD. What should I do?
I have already changed the boot order at BIOS and it still didn't work. My system is 64-bit, but does it matter if I want to install a Ubuntu 32-bit?