Boot with liveUSB on Sony Vaio

[Person of interest]

Hello everybody.

I cannot boot my Ubuntu Linux from an USB. Perhaps it is best to describe the whole process:

I followed instructions on https://help.ubuntu.com/community/In...n/FromUSBStick.

I downloaded Ubuntu 12.04.1 LTS 32 bit and then used Lili USB creator to extract *.iso file on the USB (after formatting it of course). The USB is 3.0 JetFlash from Transcend.

Then I rebooted my PC, went into my BIOS, and set Load from USB as my first choice. There was also a footnote, stating that I can boot from the USB only if an option to Load from an external device is enabled. I found the option Load from external drive in an Advanced section of my bios and enabled it. (Is there a difference between the external device and external drive? Am I missing something? )

I rebooted a couple of times but always ended in Vista OS. This is installed on a Sony Vaio laptop.

I really need your help. Tnx.