NT4 install new hotswap dives 18GB

I have a HP LXPro server that has quad Pentium pro 200 MHZ processors. I have 12 drive bays and have 4 4.5GB drives, 3 9GB drives and am trying to install 3 18.2GB drives now. I want to move data to these new drives and get the 4.5gb drives off the system. I installed the drives with no luck of the server seeing them. What can I do. I tried rebooting to see if it picked up from the start and still no luck. I can see the light go on when I plug them into their hotswap connections. I need to be able to see these drives and place them in a strip set. I am running Raid 5 with software. Help