Ext. USB HD (WD) - Can No Longer 'Be Read'


macrumors newbie
Original poster
Aug 10, 2012
Surrey, UK
Hi everyone,

The family is in tears as months of baby videos appear to be unaccessible on our external hard drive - please help!

It's a Western Digital 2tb external HD connected to our iMac via USB. Although we've had it 6 months we've hardly used it until a week ago when I copied about 200gb video files over to it. I deleted the files off the iMac to give us space to carry on working.

At the same time I thought I'd try Time Machine to back up what was on the iMac - after all, we don't want to lose data (!!).

Today, one week later, I connected the HD and got the message 'Disk cannot be read by this computer' with three options - 'Initialise', 'Ignore', 'Eject'. The latter two do nothing but the first takes me to Utilities where I'm encouraged to try fixing the disc or (gasp) format it.

Interestingly, the 'repair' option along with some others is greyed out.

The HD does not appear in Finder now, but it is listed in Utilities so I guess at some level the iMac is seeing it.

Any ideas? Honestly my wife is very distressed and I need to find some way of getting this data back! Many thanks.


macrumors 68020
Dec 14, 2010
Do not format whatsoever!
The disc seems to have developed an error - your best bet may be to take it somewhere where the data can be retrieved - not a cheap option though!
WD may look at the disk if its still under warranty (you can check the serial on their website for warranty status), but they will not retrieve data etc for you and will likely just replace the unit with a refurb.

Have you tried it on another MAC just to rule out an issue with your iMAC?


macrumors newbie
Original poster
Aug 10, 2012
Surrey, UK
Thanks for the reply. TBH getting the unit working (or getting a replacement) isn't even the main priority, it's the loss of data. What's the best way of finding a company that can recover the data - if there's any chance of being successful with this, I don't want to mess it up by going to someone who loses data whilst doing it.

As for checking on another Mac, I don't have another Mac to hand. I did however briefly check with a PC laptop and a PS3 just to see if the HD could be read without success.

Is there definitely no software solution? If OSX can see that this HD is there (it knows in Utilities that a 2tb WD HD is attached) is there no way to say 'ok, I understand stuff may be corrupted but can I take a look anyway?'.
Nov 28, 2010
To retrieve files, that have been deleted and also been emptied from the Trash or are on unrecognisable partitions or HDDs, you can use
Data Rescue 3 (trial lets you scan the HDD and see, if data is recoverable, but to actually recover files, you need to buy the full version for 99 USD) or
FileSalvage (trial lets you scan the HDD and see, if data is recoverable, but to actually recover files, you need to buy the full version for 89.95 USD).
DiskDrill - lets you recover data from HFS/HFS+, FAT, NTFS & other file systems right on your Mac.​


macrumors P6
Feb 20, 2009
I realize this doesn't help solve your immediate problem, but there's a very important lesson here and you're learning it the hard way:

If you have data you treasure, you MUST have more than one copy of it. At least two copies. Three copies are better.

That means you need a "backup of your backup drive", as well as a backup drive per se.

I have been in a similar situation, having had a partition fail on a USB drive with data I wanted -- a partition that would not mount, even though other partitions on the same drive did mount.

As others have mentioned, you can go to a professional data recovery outfit, but be prepared to pay MUCH money to get the data back, up into the thousands.

There are cheaper ways, that involve time, learning, and some money.

Here is how I recovered the data in my case (simplified):
- The partition was unmountable, and even data recovery software couldn't "see it". I had to make that portion of the drive's surface "mountable" again.
- I re-initialized the entire drive into a single partition (yes, you're reading that correctly). Now ALL the sectors of the drive were mounted, even if the drive's directory said they were "empty"
- Since re-initializing doesn't actually erase the -data- that resides on the surface platters of the drive (re-initializing wipes and replaces the -directory-, NOT the data), I could now mount the drive, and my data recovery software (DataRescue) could now "see" it and go to work on it.
- DR was able to scavenge and recover the majority of the data I wanted. I lost folder hierarchies and file names (this is to be expected), but the data itself was recovered.

If you're going to try recovery yourself, you WILL need another drive to serve as the "scratch" drive to which data can be recovered.
I suggest you buy a "bare" drive, and then get one of these:
(many shown, they all work the same, just get one that's cheap).

For recovery software, I'd suggest:
- DataRescue3
- Stellar Phoenix Data Recovery
- Disk Drill
- Nice To Recover

All work in similar ways.