Shouldn't need it with Vista but if it's a newer motherboard and sata chipset Vista may not have drivers for it. If this is the case your motherboard manual should walk you through the steps of creating a driver floppy and when to use that, along with which keys and when to press them during the Vista install to get it to ask you for them.

[EDIT]

To expand on this, if windows doesn't have any drivers for your sata chipset it will not be able to see any drives attached to it thus giving you the error of having no drives you are currently seeing. As an example, the pc I put together on saturday was could have it's sata drives seen by Vista during the install of it but XP needs a driver disc to recognize them.

Your BIOS may also give you the option of having your sata drives run in ide mode which negates the need for the driver disc during install, which was how I worked around having no floppy available to me during the XP install.