I have a Dell Inspiron N4010 laptop running Phoenix BIOS. I downloaded the Windows 7 x64 ISO to create a bootable USB. I did this under OS X by following the instructions from this website: http://blog.lewan.com/2012/02/10/making-a-bootable-usb-stick-on-an-apple-mac-os-x-from-an-iso/
I downloaded the ISO from here: http://mirror.corenoc.de/digitalrivercontent.net/
I changed the boot settings on the Dell to make the USB the first to boot, but I get the no operating system found. The USB is UDF formated. The reason I did this on a mac is because I don't have the Windows recovery CD and I can't boot into Windows.