Formatting my hard drive and installing a fresh new copy of windows 8

I have a DELL XPS 8500.  I would like to format my pc by using the factory image which is stored on a usb flash pen drive.   Once I enter the bios and go to BOOT, I find the following boot priority list:

1) UEFI: Windows Boot Manager

2) USB Storage Device

3) Internal ODD Devices

4) USB Floppy Device

5) Onboard NIC Device

Can someone please tell me which device I have to put first, second, third, fourth and fifth so that I will be able to format the hard drive?

Should I put USB Storage Device first?  Since I am going to use a usb flash pen drive to install a fresh copy of windows 8?

Thanks for your help in advance.