Results 1 to 14 of 14

Thread: external hard disk "can not be modified".

  1. #1
    Quantum Flux
    Guest
    external hard disk "can not be modified".
    I have attached my 60gb usb external hard-disk to my new poermac (my first mac) and while i can read and copy files from it i can't copy anything to it.

    when i drag a file over it says "the disk can not be modified".

    i noticed a little pencil with a line through it in the bottom left corner of the wondow which i assume means write ability is off. tried clickiing it but nothing. so how do i enable the disk to be written to?

    thanks. :dummy: (mac newb)

  2. #2

    dtravis7's Avatar
    Member Since
    Jan 04, 2005
    Location
    Modesto, Ca.
    Posts
    29,428
    Is this USB external used on a PC with Windows? If so is it formatted NTFS? If so, Mac OSX and pretty much everything else but windows NT, 2k and XP can not write to NTFS. OSX and Linux will read an NTFS partition but at this time not write to it. If your drive is formatted NTFS, I would say, go to a windows machine and convert it to a FAT 32 Partition. Most everything will both read and write to FAT32.

    If it's not a windows formatted drive then write back and we will try and figure it out.

  3. #3


    Member Since
    Dec 23, 2008
    Posts
    2
    How do you switch the format?

  4. #4

    ADKhikerVW's Avatar
    Member Since
    Aug 18, 2007
    Location
    Wilmington, NY
    Posts
    715
    Go to Disk Utility (/Applications/Utilities) and click on your drive on the left hand side. Click the erase tab and select what format you would like from the drop down menu. OS X can format a drive to FAT32 so you won't need to do it from a Windows computer. FAT32 will allow you to use the drive with either a Mac or a Windows PC, but there are some restrictions, such as files larger than (I think) 2 GB in size cannot be copied to a FAT32 drive. If you are only going to be using this drive with your Mac, then format it as Mac OS Extended (Journaled). This will give you full usage with your Mac but will not be readable by Windows.

    EDIT: Should have mentioned that if you do this, you will lose all data on the drive, so you will want to back it up first. You can copy the files from the NTFS formatted drive to your Mac, format it, then copy them back over.

  5. #5


    Member Since
    Mar 24, 2010
    Posts
    1
    so i just got my external harddrive and i am having the same problem. when i go into the erase tab it says the harddrive is set to "MS-DOS (FAT)"
    and there is no FAT 32 option. i want this to be able to transfer from mac to windows, thats why i bought it. the only other options i can change it to are 4 variations of Mac OS Extended. help

  6. #6

    Collin Bl's Avatar
    Member Since
    Apr 07, 2009
    Location
    Napier NZ
    Posts
    3,307
    Quote Originally Posted by Maximus Mischie View Post
    so i just got my external harddrive and i am having the same problem. when i go into the erase tab it says the harddrive is set to "MS-DOS (FAT)"
    and there is no FAT 32 option. i want this to be able to transfer from mac to windows, thats why i bought it. the only other options i can change it to are 4 variations of Mac OS Extended. help
    Use Disk Utility and format/erase it with this selection then you will be able to read and write to it with PCs;


    Click for full size

  7. #7

    dtravis7's Avatar
    Member Since
    Jan 04, 2005
    Location
    Modesto, Ca.
    Posts
    29,428
    Like Colin showed in his pic, MS-DOS (FAT) is FAT-32.
    ...Dennis

  8. #8


    Member Since
    Apr 14, 2010
    Posts
    1
    Same problem!
    I am also having the same problem. I have always used this external hard drive on a mac, so I'm not sure how this problem occurred.

    How do I back up my files on my EHD to my Mac HD? Just drag them all to the Mac HD, go to disk utility and reset the format (which one do I use?), and then drag them back?

    Thanks for the help!

  9. #9


    Member Since
    Apr 14, 2010
    Posts
    2
    I'm having the same problem but can't find the place with the chance to erase. When I choose applications, utilities and then the hard drive, it just opens up the hard drive and doesn't give me the erase option. Anyone?

  10. #10


    Member Since
    Apr 14, 2010
    Posts
    2
    Well I found how to do it and did it and it totally crashed my computer! WTF?

  11. #11

    Collin Bl's Avatar
    Member Since
    Apr 07, 2009
    Location
    Napier NZ
    Posts
    3,307
    Quote Originally Posted by becbirdie View Post
    I'm having the same problem but can't find the place with the chance to erase. When I choose applications, utilities and then the hard drive, it just opens up the hard drive and doesn't give me the erase option. Anyone?
    Welcome to the Forum. For help you need to be a bit more informative about what exactly you did - what actions caused the crash and what you mean by crash. What are you trying to erase?

  12. #12


    Member Since
    Apr 09, 2010
    Posts
    21
    Apple - Downloads - System/Disk Utilities - NTFS-3G

    Install that and you should then be able to write to NTFS.
    21.5" iMac 3.06 | 8GB Ram | 500 GB Hdd
    11" MacBook Air

  13. #13


    Member Since
    Apr 09, 2009
    Location
    Ithaca NY
    Posts
    2,073
    Quote Originally Posted by becbirdie View Post
    Well I found how to do it and did it and it totally crashed my computer! WTF?
    Haha, you selected your boot drive and not the external drive. You effectively zeroed out the data on your boot drive and need to reinstall the operating system and all of your applications.

  14. #14


    Member Since
    Apr 09, 2009
    Location
    Ithaca NY
    Posts
    2,073
    PS - Sorry for laughing, and I may be wrong... but it sounds like that's what you probably did. And if you did, it's very not funny for you. But still pretty amusing to me. People should really put a warning up when they talk about formatting drives. I always make sure to say "select the external hard drive - do NOT select your boot drive."

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 9
    Last Post: 03-12-2013, 02:06 PM
  2. External Drive "cannot be modified"
    By mcnabb10 in forum Other Hardware and Peripherals
    Replies: 2
    Last Post: 05-10-2010, 07:41 PM
  3. help with writting to external hard disk (LG 2.5" External HDD 320GB)
    By krissieleo in forum Other Hardware and Peripherals
    Replies: 0
    Last Post: 06-27-2009, 07:22 PM
  4. External HD Says "Disk Full" bout 800 GB is Free
    By spolebitski in forum Other Hardware and Peripherals
    Replies: 0
    Last Post: 12-20-2008, 09:48 AM
  5. Replies: 0
    Last Post: 08-30-2007, 03:09 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •