Not recognizing external hard drive

when i plug in my external drive, this message comes on "the disk you inserted can not be readed by this computer. (format) (ignore) (eject)"

what do i do?

First try a new cable and if that doesn't work, try a new enclosure. If that fails, try formatting the drive.

I tried different methods and finally one method solved my problem: install the latest Paragon Driver for Mac OS. Once you restart your mac, it will work out. Here is the link:

http://www.seagate.com/support/downloads/item/ntfs-driver-for-mac-os-master-dl/

OS X is able to read NTFS without a driver. I used to use Paragon until it became apparent that it was the cause of a number of intermittent problems. If I need compatibility with Windows I just format the drive ExFat since OS X supports it natively.

I don't think OSX supports NTFS reasonably well, even the latest version of OS X. I already see a lot of reading issues with hard drives using NTFS. Unfortunately many of the Windows users have a NTFS formatted hard drive, and it simply doesn't work on OS X. This is something Apple should really solve.

Okay so I know this feed is really old, but I had the same problem and I managed to solve it. You need to get your hands on a Windows Machine. Plug in your hard drive, then open the start menu. Right click on "Computer," and go to "Manage." In the bar on the left go to "Disk Management." Your hard drive is presumably "disk 1." Right click on the middle volume for your disk (not the unallocated volume, or the boot volume). Then click "Delete Volume." Now that the information is deleted, unplug your HD and plug it into your Mac. Go to "Disk Utility" and it should recognise it. It should automatically offer to reformat the disk. Make sure to reformat it as "OS Extended (Journaled)." Now you should be able to use it.

I hope this works for you, and good luck!

I have a 1TB Western Digital.

It's not being read by my iMac anymore. I have the latest 27" 4k retina

It won't show up in Disk Utility either.

I took it out of the WD case and am using a USB 3.0 external enclosure with it's own power source.

Turns on, disk is spinning but nothing is showing up still.

I connected to a Windows computer and it connected as an external enclosure but it never showed up amongst the hard drives.

All the uses were checked except a big X for "Mass USB Storage Drive"

So I'm assuming the disk is dead.

Dang I'm an idiot. Same issue here, putting 3.5 internal into docking station. Spent way too long before finding this and doing the obvious "turn it off and turn it on again." Just here to verify for future others (probably me) that this solved my issue as well. Thanks @jacksonian71!

Hi. I've spent a lot of time scouring the internet looking for help.

-I have a 500GB Western Digital My Passport external USB drive and a 1TB Western Digital My Passport external USB Drive. Both are formatted OSX Extended Journaled.

-My computers are:

1 - 2011 MacBook Pro 13" (personal)

2 - 2012 MacBook Pro 13" (work)

3 - 2012 MacBook Pro 13" (work2)

All three systems are running the latest version of OSX El Capitan.

Both external drives are no longer being recognized by my work systems, computers 2 and 3.

Nowhere in Finder, Disk Utility, or anywhere else. They used to be, but after upgrading to El Capitan the disks stopped showing up anywhere on these machines. The disks are getting power and spinning, though.

However, both drives show up on my personal system, computer 1 - immediately and work flawlessly!

I'm at a loss because 2/3 of my systems no longer recognize the external drives.

I've powered down, changed cords, stood upside down, chanted, sung some songs, and caressed the machines nicely.

Any help, please?

Thanks!

hey guys. if this can be an option for you, erasing the disk in disk utility worked for me. popped right back up after erasing it. hope this helps anyone

I have a Seagate 2 tb external HD that just spun and made a beeping noise when plugged into my keyboard. Read the above post and moved to back of iMac. Working well now. Thanks

Thanks! I tried the link. now my Seagate HDD got detected and working fine.

Thanks. The suggestion to "verify disk" worked for me.

Thank you.