Start up and boot from USB

[Komeda]

I have problem trying to start up snow leopard from usb. When opt is pressed down the start unit "usb" won´t come up only my osx and win boot alternative.

Is this usb (attached pic) correctly formatted?

Is´s problem because i also run bootcamp?

/ K

 

[simsaladimbamba]

Does it show up here?

System Preferences > Startup Disk*

How to format a new HDD to install Mac OS X onto (or make a bootable copy onto)​