Do what RealBeast says. The thing you don't seem to know is that, when you connect any new HDD to your machine, it is NOT part of any RAID setup already running. No HDD becomes a part of a RAID array unless you specifically assign it to RAID using the RAID management utilities in you BIOS. So the new HDD you attach is automatically just a plain stand-alone SATA HDD. Like any other new HDD, it will require Initialization via Disk Management as RealBeast said.