Sorry, we don't do private replies here. This forum is supposed to help
everybody.
To the question:
You can only boot from usb if your bios supports this. Set the first boot device to "usb mass storage" or "external usb" or whatever your bios calls it. Make sure grub is installed to the usb drive. Distros usually have instructions on how to install to an external drive or a usb-key.
Have fun
