Microsoft Ought To Make A Bootable DOS Thumbdrive Image Available

I need to flash my motherboard BIOS in order to install Vista on my dual-processor desktop (I hope that will do the trick). I don't have a floppy drive anymore, not on any machine. I can't believe what a problem this has turned into. I go through my half-a-dozen rescue CDs -- all of them are either utility-specific or Linux-based. The flash program from Tyan, though, is DOS-based. I started to follow the instructions to make a bootable thumbdrive, but they rely on a bootsect.bin extracted from a floppy! Back to square one. (P.S. Please don't send me a bootsect.bin -- I'm a trusting soul, but I'm not that trusting.)

I wish Microsoft had a "format thumbdrive to boot DOS" utility.