Adding a new hard drive

I have NT 4.0 server installed on a Compaq Proliant. I added a hard drive to the server and thought disk administrator would recognize the drive. It did not. I rebooted and still the drive is not there. I am assuming this may be due to the fact the drive is not formatted.

I have a raid three in the system as one logical drive with two partitions. There is another drive that is independent and the fifth drive I just added. I want this drive to be independent as well. I do not want to expand the raid.

I am not sure were to start my approach. Could someone point me in the right direction?