Why can’t I access files on my external hard drive now that I use a Mac?

Vicki December 22, 2011
Whatsapp Pinterest

I recently changed from a PC to a Mac. Now I can’t edit or save any files to my external hard drive, which I used with my PC. How do I gain permission to edit and save files with my Mac using the same hard drive?

  1. Jon Igoe
    July 24, 2012 at 1:12 am


    Just looking for some advice on my external hard-drive. Just recently it began acting up, were files disappered or became inaccessable, the file type shows as "File" consisting of a plain white icon that will not open and also shows the file name as "USBC¿ÈÑä.". I recently ran the drive through an antivirus scan (AVG) which detected as dangerous threat which was repaired. However, this seemed to make no difference the the problem. the file consisted of jpegs, mpegs wma mp3s and some others and the disk space remained the same even though some file have visually disappered. I would extremely thankfull if you could supply an answer to this problem. Thanks :))

    • Mike
      July 24, 2012 at 4:19 pm

      AntiVirus software does not really "repair" threats but remove the infected part(s).

      If the malware simply added itself to the jpegs, mpegs, etc. there is a (very) small chance the files are still usable.

      In your case however it seems the malware has overwritten some parts of the files. Now after removal the files are simply incomplete and corrupt – nothing you can really do about.

    • Bruce Epper
      July 24, 2012 at 8:46 pm

      There are several types of malware that rename your files as well and this could be what happened here since Windows ignores magic numbers and simply uses the file's extension to determine file type. You can download the file utility from the GnuWin32 project and install it on your computer. It is a command-line utility taken from Unix that checks the file header in order to identify the file type. If it identifies a known file type (doesn't simply return a value of 'data'), you can rename the file with the proper extension. You can then try to open the file with the appropriate program and give it a better name than the current random mix of characters.

  2. Takeo
    June 27, 2012 at 3:32 pm

    Hi, my problem is that I can't see any device NTFS on Disk Utility.
    I have 1Tb HDD SATA2 for data only that is NTFS and a Seagate 1Tb FreeAgent GoFlex Externa Drive also formated as NTFS. Both can't be recognized in Disk Utility.

    After formatting External HDD as ExFAT, it was recognized on Lion and Windows, but NTFS HDD still not be recognized, and I don't want to format it as ExFAT.

    Why can't I see NTFS devices for read only ? I know about mcfuse, but first, device should be detected in Disk Utility.

    • Susendeep Dutta
      July 6, 2012 at 2:33 pm

      I think that your external HDD is not getting mounted by Mac 10.7.One user of Apple support communities found a solution for this -


      " nik pel : - Try deleting /System/Library/filesystems/ufsd.fs and install your Paragon/MAfuse/Tuxera implementation

      Worked for me. "

      If your disk ever gets detected by disk utility by chance,then try to repair it using Repair Disk command.This will make sure that the bad sectors will get fixed and will be readable in Windows/Mac computers.

  3. Lisa Rauter
    June 12, 2012 at 4:58 pm

    thats great can some one help me with the same situation

  4. Robert Pearson
    May 9, 2012 at 9:00 am

    I currently have seven external HD's connected to my Windows based PC. I am on the verge of buying a Mac PC and would like to know if the externals drives will work on the Mac. These drives mostly contain .m4p and m4v files. One drive however contains only standard stuff like .doc, .jpg, etc. If there's a program out there that will fix any potential roadblocks let me know. I really like the idea of getting the mac but have too much invested in the contents of the seven external HD's.

  5. JTACK
    April 21, 2012 at 2:17 am

    I have a Toshiba Laptop and a Toshiba external hard drive...  I plug the external hard drive into my MAC BOOK PRO and it never recognizes it.  I plug it into my husband's Mac Book Pro and it instantly recognizes it...  Any suggestions?

    • Oron Joffe
      April 21, 2012 at 9:22 pm

      Try plugging it into a different USB socket. 

      I'm guessing that it's a portable hard disc (that is, one without a separate power supply). Some hard discs require a little more power than others, and some USB sockets provide a little less power than others... If you have a combination of the two, you have a problem, hence my suggestion.

    • smayonak
      April 21, 2012 at 10:00 pm

      Your situation is the reverse of the usual problem. Normally Mac formatted external drives aren't recognized in Windows 7, not the reverse. Newer versions of Mac OS X can read stuff in NTFS (Windows), but it can't write to a Windows partition. There are software solutions available that resolve this issue, but they cost money. Or have a free trial period.

      Later versions of MacOS X added partial support for writing to Windows formatted partitions, like external drives, but last I read, these were not completely feasible and have to be enabled in order to work.


      Also, older versions of OS X may not be able to mount NTFS or FAT32 partitions by default. I believe this can be fixed by enabling the write to NTFS as detailed in the article below:


      The directions are for Snow Leopard by the way.

      Anyway, good luck!

      • smayonak
        April 22, 2012 at 2:44 am

        I found directions for recognizing a Windows formatted external drive in Mac OS X:


        However, the MacFuse software is now no longer in development. There's specific mention about its bugs in Lion.

      • Jonnph
        May 4, 2012 at 12:58 pm

        Hi got this problem, is there a way or a software about this? --Mac formatted external drives aren’t recognized in Windows 7

        Please help. Thanks!

    • ha14
      April 22, 2012 at 8:05 am

      Do you have the same OS in your MAC BOOK PRO and Your Husband MAC Book Pro.

      Toshiba Acknowledges MacBook Woes in Canvio USB 3.0 Hard Drives
      MacBook Pro (Early 2011) Not Recognizing Toshiba Canvio USB 3.0 Hard Drive

  6. anurag singhal
    April 13, 2012 at 6:13 pm

    I recently moved to a new company but before leaving my last one I copied over some Files and Folders from my work laptop to an external Hard drive but when I try to access those files on a different laptop, I am getting "you don't have access or privelege" or "Your document could be read only or encrypted". Please help how to overcome this issue as I have last 4yrs of data that I need to access :( I am tried to override the permission and stuff but still no luck. I can see all the data on my external harddrive though at least that is one good thing.

    • Bruce Epper
      April 22, 2012 at 1:09 am

      You most likely don't have permissions to override permissions on the files.  You need to take ownership of them instead.  Haven't had to do this with XP in so long that I can't remember the exact steps to do it.  A quick check on the properties of the files/folders should give you a Security tab where you can take ownership of these files and folders.

  7. robotsvictorious
    February 3, 2012 at 3:19 am

    Hello, I'm having a similar problem.  My issue is that my old PC is no longer recognizing the hard drive.  It tells me that it will need to be formatted. 

    So basically, I have an external hard drive formatted in NTFS that is read-only on my Mac and just...blank...on my PC.

    Anyone have any ideas on how to get my files off this hard drive so I can reformat it?  

    • Anne Reilly
      February 17, 2012 at 12:40 pm

      "Once reformatting is finished, make sure to check the info of the drive by selecting the new formatted drive and clicking theApple key + i keys together"



      • AnneReilly
        February 17, 2012 at 12:55 pm

        PLS HELP

  8. Anonymous
    December 22, 2011 at 9:23 pm

    How To Format A Large Hard Drive With Either FAT Or FAT32

    • Annoyed!
      April 9, 2012 at 11:53 am

      I have done this but now my Windows computer cannot detect the hard drive at all. Only the mac detects it! How do i transfer all my files on my windows to the mac via the hard drive?

      • ha14
        April 9, 2012 at 12:05 pm

        first lets try to make windows recognize hard drive:
        on windows
        go to device manager and look for yellow exclamation point beside a device, if it is there then right click on it and choose uninstall. Then reboot pc and plug in external hard drive.


        1) Right-click on “My Computer” then Click on “Manage”
        2) Double-click “Disk Management” You will probably see external hard Disk
        3) Right-click in the left portion of that drive box External Disk
        4) Click “Initialize” and “OK” in the next dialog box. Wait few seconds and it should now say “Online” in the box.
        5) If there is no assigned drive letter, right click on the big space of your external hard drive then choose Assign drive letter or Change Driver Letter and Path

        Start > Run "cmd"
        type--> diskpart
        type--> list volume
        type--> select volume #
        type--> attributes disk clear readonly
        type--> x:>attrib -r /s /d (X= External hard drive)

  9. Kryptonite
    December 22, 2011 at 3:28 pm

    you went to the dark side and your hardware is punishing you, right your wrongs by ridding yourself of the evil you have allowed in your home and all will be well again

    December 22, 2011 at 6:19 am

    Hello, if you were using this external drive in windows, that means that it could be formatted in NTFS or FAT32.  From what you are saying, I gather that your drive is probably formatted with NTFS file system. 
    If the drive is formatted in NTFS, a MAC will only be able to read it, not write to it unless you have something like the following:


    If the drive is formatted in FAT32, you would be able to access it in MAC with read and write functionality. 

    You have two options, make sure drive is formatted to FAT32 and access it with windows and mac, or format the drive to HFS+.  HFS+ is the format used in MAC computers.  I would only use HFS+ option if you are only going to be using it in MAC.  If you decide to format your drive to either choice, make sure to back up the contents of your drive and then do the formatting.  Once formatting is done, you can move the content back....if you do not do this, you will loose the content.

    • Vicki
      December 22, 2011 at 6:44 pm

      Hi, Thanks for your reply. Yes, the format for the external hard drive is NTFS. Could you show me how to reformat the hard drive?


      • FIDELIS
        December 22, 2011 at 11:17 pm

        Hello, make sure to move the files in external hard drive to your computer before reformatting drive.  Once your reformat drive, all contents will be lost.  if you are using your mac to format the drive, this is what you do:

        -- connect external drive to mac
        -- click on applications
        -- click on utilities
        -- select Disk Utility
        -- you should see all the partitions on the left
        -- make sure to select your external drive from options shown in the left.  Check by name of drive or size
        -- make sure to select the right drive
        -- once drive is selected, select erase at top of screen
        -- make sure to select Mac OS extended (journaled) for volume format option
        -- change name of drive if you like to make it easier for you to recognize
        -- once all the information is entered, select erase at bottom of screen
        -- click on erase
        -- Once reformatting is finished, make sure to check the info of the drive by selecting the new formatted drive and clicking the Apple key + i keys together
        -- if you backup the contents of files before, reformatting, copy/move contents back.

        Let me know how it goes.

        • Stephanie RiCharde
          January 18, 2012 at 1:11 am

          It worked for me.  Thanks so much!

        • FIDELIS
          January 18, 2012 at 1:23 am

          Hello, I am glad it worked for you

        • Bknitting
          January 22, 2012 at 7:05 pm

          This worked for me also and I want to thank you for the great advise!!

        • FIDELIS
          January 23, 2012 at 12:21 am

          Hello, I am also glad it worked for you.

        • Cat
          April 9, 2012 at 11:55 am

          I have done this but now my Windows computer cannot detect the hard drive at all. Only the mac detects it! How do i transfer all my files on my windows to the mac via the hard drive?

        • FIDELIS
          April 9, 2012 at 9:26 pm

           Hello, if you want both your mac and windows systems to recognize the drive, it has to be formatted with a format both systems understand.  I would say, format the drive with FAT32, that way both mac and windows can read it.

        • Mark Hall
          August 4, 2012 at 12:15 pm

          I know its a little late but, oh my gosh I love you xD haha just got a hard drive off the internet only to find it says only Windows 7 compatible! Thanks so much for the step by step, really helpful!

Ads by Google