Hey there, i did this last night! Workbench 3.1 comes with 6 disks, you need them all to do an install as far as i know, You will need to format the drive and partittion it ( i think -correct me if im wrong, this is what i did last night). The workbench disks then have an install proggy to run them and then you dont need the disks, it boots off the drives. :-D
