My Mac Won T Recognise My External Hard Drive



My Mac Won T Recognise My External Hard Drive

What To Do If External Hard Drive Is Not Detected On Mac

My wife has an iMac with OS X Lion on it. We partitioned her HD to run bootcamp with Windows 7 to play some games. Bought a Seagate Backup Plus external USB HD for extra space for games on the Windows 7 end and Time Machine for her iMac. Time Machine does not work with the Paragon driver the ext HD came with so I decided to partition it into two parts; one for Mac, the other for Windows.

I looked up about the different HD formats for Mac and Windows. Used Disk Utility to partition the ext HD 50/50. Named the top partition Mac and chose the format Mac OS Extended (Journaled), named the bottom Windows and chose the format NTSF.

After running Time Machine on the Mac partition I restarted the iMac to Windows 7. I did not eject and unplug the ext HD before restarting, not sure if it played into my problem or not but thought I'd mention.

Hello, i’m trying to install my new WD My Book Essential hard drive to my Mac Snow Leopard. I’ve tried reformatting it, but I can’t do that until the computer recognises the drive. I’ve tried downloading the virtual installation cd, but the software doesn’t get past ‘drive not found’. I’ve tried plugging it into another mac, and a pc, and neither of those recognise it either.

Once Windows 7 started I opened up My Computer and I did not see the ext HD listed. I ran Disk Management and saw the ext HD listed but it did not show any partitions. Just shows the entire ext HD unallocated.

What do I need to do in order for Windows to see the necessary partition?

  1. Solution 1: Check if your Mac can recognize the external hard drive. This kind of approach makes you able to check whether your mac port or hard drive is physically damaged. If your mac book/ pc port or external drive is damaged, your Mac will not identify the external hard drive. And you will get the same dialogue on-screen as I showed above.
  2. I have an iMac running OS 10.11.6 (El Capitan). When I plug in my Apple external CD/DVD drive, the drive does not show on the desktop or in the sidebar. I have already done the following: Made sure that external disks, hard disks, CDs, DVDs are all checked in my Finder 'General' preferences.

Been reading up on the different 'options' for the partitions; i.e. GUID and MBR.


I originally read that link you provided before I was having the issues. I solved the problem yesterday. I changed the Windows partition on the external HD to MS-DOS, ejected the HD, rebooted into Windows 7, plugged in the HD, Windows saw HD right away, went into Disk Management and changed the Windows partition from MS-DOS to NTSF.


Thanks for everyone's help.

Thanks for your feedback:) your valuable solution will help others:)

Mac External Drive Not Showing

Did you install the Bootcamp tools after installing Windows? Because that's essential if you want to see these drives. Simple thing, I know, but I thought I'd check.
I am a bit surprised you are having issues because your iMac and OS X version suggests that the drive is most likely formatted using the GUID/GPT partition scheme which Windows 7 should have no issues with reading.

Actually, being curious I just tested it with Lion and Windows 7 (no bootcamp):

My Mac Won T Recognise My External Hard Drive For Windows 10

I partitioned a drive with one OS X Extended partition, one ExFAT using the GUID partition scheme and Windows detected the ExFAT partition right away.

Maybe it's a derp from bootcamp? Anyway, the options you were reading up on are most likely the solution to your problem.

Since you only used Time Machine so far and Windows couldn't even access the drive I assume you have no problem with formatting the drive again losing all data currently stored on it?

My Mac Won't Recognize My External Hard Drive

Go into Disk Utility, select the external drive and click on the partition tab.

Select 2 partitions etc. as you did before ~ OS X Extended for Time Machine, ExFAT or Free space for Windows. At the bottom click options and select 'Master Boot Record'. Then finally apply the settings and let the drive partition.

Maybe bootcamp only likes MBR partitions ~ hope this solves your issue.

have you tried to use windows restore point to revert back just before the problem started?

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How Do I Get My Macbook Pro To Recognize My External Hard Drive

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