aLone

Hello, i have a Notebook and Usb External Case with LG DVD-Writer. I can't boot my computer from usb devices. Because, it's not available in the bios boot section. So, i can't boot my computer from the Longhorn bootable DVD. I want to setup longhorn to clean/formatted hard disk partition. I tryed to setup lh under the dos, but it didn't work. The setup.exe don't run in the ms-dos. Is it available parameter for the setup under the dos? What can i do? Could u help me please? By the way, can i edit the dvd boot image and write to bootable cd for the show longhorn setup/boot folder under anyone hard disk partition ?