Right-click the my computer icon in the OS and choose “manage”. Look at the disk management and see if the space is showing there. You might need to use diskpart to get the space to show in the OS.
Utilizing the HP Array Configuration Utility, you should be able to see all the drives straight from the server hardware. There I would do the modification of the array if needed here. Then if the utility sees it, then you go within “Computer Management”. Then go to “Disk Management” and right-click and then select “Rescan Disks”. It should now show up within this interface.