monline

Many utilities (eg. firmware patches for CD/DVD drives, RAID controllers, etc.) require you to boot into DOS. However a lot of configurations (especially servers) come with only an optical drive, so you cannot use a floppy to boot into DOS. Not even to talk about the capacity of a floppy disk ... a RAID controller firmware might not even fit onto a single 1.44MB floppy disk. Fortunately newer motherboards already support booting from an USB device, but putting DOS (or something equivalent) onto an USB drive and make it bootable is not a trivial task.

Of course recent Windows versions provide no support for making a bootable USB drive. However there's a small utility made by HP (follow this link or search for "HP USB Disk Format Tool") that can help you even in a pure Windows environment. For this you'll need the Win98 boot disk files in some directory of the machine where you're going to use the HP format utility. You can fetch these files from here or grab a boot disk image from bootdisk.com and extract its contents (eg. with Winimage).

The procedure is most simple: connect the USB drive to the PC, start the HP format utility, select FAT32 filesystem and check the "Create DOS startup disk" checkbox and select the directory with the Win98 bootdisk files. Click start and enjoy.

Note: don't forget to eject the USB drive in Windows before unplugging!
Note2: it's important to use a Win98 bootdisk. I tried with a DOS v6.22 bootdisk too, but it didn't work.