Did you boot into Windows from the flash drive or did you install Windows from the flash drive?
If you booted from the flash drive, you're going to need to recreate your boot device with the necessary drivers slipstreamed into the ISO.
If you installed Windows from the flash drive, you need to use the computer you used to post this thread, go to your motherboard manufacturer's web site, download the necessary drivers onto a flash drive, transfer that drive over to your system and install from there.
-Wolf sends