This page describes several alternatw methods for adding disk to Windows systems
In Server Manager go to File and Storage Services - Disks, right click on one of the the new disks and choose New Volume.
This will initialize the disk in GPT (GUID Partition Table) format. If you need MBR (Master Boot Record) format then use the Disk Management method (see later on this page) instead.Type diskmgmt.msc from a command prompt (e.g. Powershell) OR in Server Manager choose Tools - Computer Management - Disk Management
TODO ** Not Yet Fully Tested ***
Assumes your newly added disk appears in Get-Disk as Number 1 with an OperationalStatus of Offline, and you want to mount it as drive G:...
Get-Disk
Set-Disk -Number 1 -IsOffline $False
Initialize-Disk 1
New-Partition -DiskNumber 1 -DriveLetter G -UseMaximumSize
Format-Volume -DriveLetter G -FileSystem NTFS -NewFileSystemLabel "SQL Backups"