stillblue :
When in the BIOS was your USB plugged in and did the BIOS see it? ie was it a boot option? If not, check and see if there is a + next to harddrive and if yes click it and promote your USB.
Are you sure the image was installed rather than copied to your USB? How did you install it?
I followed instructions in google and made a liveusb by installing a .iso file into the usb. Ubuntu was installed on the laptop when bought it, so I have no liveusb (I did installed later win 7, than back to ubuntu, I used installation cd, but I already made a live-usb).
The bios see my disk on key, his manufactour written there in the boot options. Two options in boot:
LEGACY boot- with 4 options- I choose usb
and UEFI boot- with only option: (EFI USB1 PATH1 (SANDISK CRUZER BLADE).
What am I doing wrong?
Update- I did it! I'm inside, I'll update, right now checking disc for defects (one of the options that featured there).
2 files with errors found, now I'll try to check what you told me.