How to make a read-only filesystem writable

Question

We have some gotten various files on some hard drives from somewhere. I would like to reorganize the files on there and add some more, but when I try to do that I get an error saying the drive is a read-only filesystem. Finder won't let me do anything to it, and can't do anything in the Terminal either.

How was the drive made read-only in the first place? How can I make it writable?

I am not Mac OS X 10.6, and the drive when mounted says FREECOM HDD. Have access to a Windows computer as well if needed.

When I click on the Info button in Disk Utility on the drive I get the following info:

                Name :  SAMSUNG HM160HI Media
                Type :  Disk

Partition Map Scheme :  Master Boot Record
     Disk Identifier :  disk2
          Media Name :  SAMSUNG HM160HI Media
          Media Type :  Generic
      Connection Bus :  USB
   USB Serial Number :  10D0B58436FF
         Device Tree :  IODeviceTree:/PCI0@0/EHC1@4,1
            Writable :  Yes
           Ejectable :  Yes
            Location :  External
      Total Capacity :  160.04 GB (160,041,885,696 Bytes)
   S.M.A.R.T. Status :  Not Supported
         Disk Number :  2
    Partition Number :  0

And on the volume:

                       Name :   FREECOM HDD
                       Type :   Volume

            Disk Identifier :   disk2s1
                Mount Point :   /Volumes/FREECOM HDD
                File System :   Windows NT File System (NTFS)
             Connection Bus :   USB
                Device Tree :   IODeviceTree:/PCI0@0/EHC1@4,1
                   Writable :   No
Universal Unique Identifier :   DE1A6D72-14C0-4CEC-AB76-A26A53E1B1C7
                   Capacity :   160.04 GB (160,039,240,704 Bytes)
                 Free Space :   88.94 GB (88,935,407,616 Bytes)
                       Used :   71.1 GB (71,103,832,064 Bytes)
            Number of Files :   129
          Number of Folders :   0
             Owners Enabled :   No
        Can Turn Owners Off :   No
           Can Be Formatted :   No
                   Bootable :   No
        Supports Journaling :   No
                  Journaled :   No
                Disk Number :   2
           Partition Number :   1

I mean... they have to have had it writable at some point in time. How would they otherwise get the files there? How can I make it writable again?

Answer 1

OS X can read NTFS volumes but not write to them. You will need third-party software to enable writing. Here is a mention of one possibility.

More recent information says that Snow Leopard has the ability to enable writing (it's disabled by default). This page has information on adding an entry to the fstab.

You should be aware that there is a risk of data corruption.