Formatting WD external hard drive issues

Hi There,

I am new to these forums and it looks like I might have finally found a place to find the answer to my question!

I am having some problems formatting a wd my passport essential external hard drive to my mac. This hard drive was in windows format originally and was a friends, so I deleted a couple files on it on a pc then plugged it into my mac to do the whole erase and format/partition procedure. The problem is, upon it erasing, it stopped at the end and said something about an error and it could not be completed, yet the drive seems to be erased (because the one volume that was in it is no longer there when looking at disk utility). However, now when I plug it into my macbook, the computer says something about it not being able to recognize drive and it takes me to disk utility (it won't even pop up on my desktop). I try the whole process again, and same thing.

Anyone have any suggestions? I went on the wd website, and there is software to download that I think will help, but there are so many options I don't know what to download. I'm not a super computer genius, so the more detailed the instructions, the better, lol!

Thanks so much in advance!

G'day and welcome to the forums.

When connected to the MB can you see the drive in the left hand pane of Disk Utility?

If so select the drive by highlighting, go to erase, format Mac OS Extended (Journalled) and erase. Then into Partition, make one single partition and under Options make sure GUID partition table is selected.

If you get it formatted suggest using SuperDuper or Carbon Copy Cloner to clone the internal to the external which will be an exact copy, and will be bootable in case of emergency.

Personal favour SuperDuper as the restored offers a say weekly Smart Backup which takes about three minutes.

Thank you for responding!


I have followed directions found online to a T. Every time I go to "erase" and reformat, it deletes any volumes there, to which I think, ok I'll make a new partition (like suggested) and then try the whole process again. The partition won't even create.

When I go to erase the drive and reformat to mac os extended journaled, I get:

Disk Erase failed with the error:

POSIX reports: The operation couldn’t be completed. Input/output error

When trying to partition, I get the following message:

Partition failed with the error:

Wiping volume data to prevent future accidental probing failed.


And... once doing all of these steps, then when I go to plug in the drive again, it no longer recognizes it and says:
"The disk you inserted was not readable by this computer."

Sounds like the drive may be failing.