Just to add, tried using diskpart in the command prompt and get a little more information in terms of error messages. This time:
_ DiskPart has encountered an error: The parameter is incorrect. See the System Event Log for more information. _
So I checked the System Event Log and found an error and warning of note:
_ Error: The driver detected a controller error on \Device\Ide\IdePort2. _
Warning: The IO operation at logical block address 0x5bd008 for Disk 11 (PDO name: \Device\Ide\IdeDeviceP2T1L0-12) was retried.