I ran into a problem trying to flash the BIOS on a Dell server recently. I downloaded and ran the Windows BIOS installer, but it would not work. It would either stall or finish and say reboot. At reboot, the server would get stuck going through its checks and the hard drive would show constant activity. After a while I nervously powered off the server and started it again. It booted fine, but the BIOS was not updated. I noticed there was a DOS BIOS update available so I decided to download it. However, I needed a way to boot the server into DOS to run the BIOS update.
After some searching I found a program called Rufus here. It is a free standalone program that creates a bootable USB drive. You can create a bootable drive from an iso file or create a bootable DOS drive (it comes with a free version of DOS). I created a DOS drive with a 2 GB USB key. I copied the BIOS updater on to the drive after it was ready and successfully used it to update the BIOS on the server. Rufus is a great tool for creating bootable USB drives. It solved a problem for me; maybe it can do the same for you.