11-12-2005, 08:56 PM

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)

11-12-2005, 09:23 PM

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.

12-23-2008, 07:10 PM

How do you switch the format?

12-23-2008, 09:04 PM

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.

03-24-2010, 02:42 AM

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

03-24-2010, 03:19 AM

Originally Posted by Maximus Mischie

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

03-24-2010, 03:50 AM

Like Colin showed in his pic, MS-DOS (FAT) is FAT-32.

04-14-2010, 12:21 AM

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!

04-14-2010, 06:49 PM

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?

04-14-2010, 07:11 PM

Well I found how to do it and did it and it totally crashed my computer! WTF?

04-15-2010, 04:10 AM

Originally Posted by becbirdie

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?

04-15-2010, 07:38 AM

Apple - Downloads - System/Disk Utilities - NTFS-3G

Install that and you should then be able to write to NTFS.

04-15-2010, 05:39 PM

Originally Posted by becbirdie

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.

04-15-2010, 05:50 PM

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."