USB flash is not recognized in BOOT menu

[mondoteq]

Help, I don't know what to do.
I wanted to make a dual boot (linux over windows). First time everything was okay but I didn't manage to install it(it was too late).
Today when I tried again to install linux but my laptop doesn't recognize my USB ! It's visible in computer, but not in boot menu, On other laptops it works

[DaveLembke]

What is make/model of the laptop having issues with USB boot?

 Some older laptops dont have USB boot option, however maybe its just that you need to change the boot order in the BIOS to boot from USB first, CD/DVD drive second, and then HDD third.

[patio]

How did you build this boot disk ? ?
You cannot simply copy a Linux distro to a flash drive and expect it to boot...