I installed 5.1.2 on a machine using software raid with no problems at all using the adaptec 29160n. The drivers for this card appear to be the same as the 19160 so I would think that there should be no problem for your card. Are you using LVD drives and are they being detected in the SCSI bios. Have you used the correct termination. The cable should be terminated (not by the drive but at the end of the cable with a special terminator block) and the cable needs to be the type with twists in it. The terminator must be at the end of the cable that has two connectors near each other and one of the drives must be at this end of the cable (one from back the end).Can you create a partition under DOS. Have you set the drive ID to 0 and 1 respectively.Have you only got LVD drives on the bus as SE (Single Ended) will work but everything on the bus will slow down to that speed taking away the advantage of ultra 160. I was very impressed with the speed of these SCSI cards when I did the install it took less than 3 mins to create the partitions and copy everything over and to start the configuration process.