I recently cheaped out and bought a whitebox server to use for my virtual machine test environment. During installation of Windows 2008 R2, it needed the RAID drivers. I didn't put a lot of time into testing this, but most of the time the drivers need to be on a floppy disk (at least they did for earlier operations systems). The motherboard documentation said I needed to get a USB floppy drive.
My alternative was to go into the BIOS of the new system, go into the USB settings, and force the attached USB drive with the storage drivers to be seen as a floppy. Normally, the USB storage autodetects, and a large drive like a 8 GB USB drive will be seen as mass storage.
I was able to browse to the drivers of the USB drive and all was good.