That is of course the SATA controller driver which should be available on the motherboard companion CD.
If a floppy drive isn't available, then you've got some work to do!
As a slight aside to this, virtually every "floppyless" system that I've seen does in fact have a floppy controller on board. For the sake of a bit of peace and quiet, I usually fit a floppy drive where the case has provision.
To use an upgrade CD, you'll need a Win98 CD or similar to verify previous ownership.