The Promise card works without any drivers whatsoever. You create your RAID volume using the utility embedded in it's BIOS. From there, the RAID volume appears as one large hard drive using standard BIOS calls (IOW, fdisk would work the way it normally does). The drivers are needed for performance reasons, no matter what the OS is. If your OS can access the hard disk through the BIOS then it will be able to talk to the RAID volume (example, Windows 98 in safe mode). Most modern operating systems bypass the BIOS because it's too slow, hence the need for drivers.