Hi all, So I am trying to reformat my macbook pro to factory settings, which includes removing partitions and wiping the hdd. I restart my macbook into recovery mode - went into Disk Utility - erased the hdd on both partition(I have 2) - tried to remove 1 of the partition but I got an error message. "Partition failed - Partition failed with the error: Couldn't unmount disk." I've tried looking this up but the error is pretty general and couldn't find a sure fix. Can anyone help me out? Any advice would be appreciated. Thanks in advance!