How can I fix/replace/copy files on an NTFS partition from outside Windows NT?

A. NT Internals has released ERD Commander which allows you to perform read and write operations on NTFS/FAT and CDFS partitions. ERD Commander can be purchased from or a free read-only version from

Once downloaded just run the executable erdcmndr.exe and it will self install to a directory of your choosing. It will also create a program group "ERD Commander". Once installed it will ask if you want to create the ERD Commander disks. ERD Commander works by altering a set of NT installation disks with its own special versions of certain files so instead of installing NT it brings up a DOS like command prompt. You can either modify an existing set of installation disks or let ERD Commander create a new set (you will need to insert you NT installation CD-ROM). The instructions below are for creating the disks.

  1. Run "ERD Commander setup32" (start - programs - ERD Commander). This is assuming you are booted in NT, if you are running a 16bit OS you could run "ERD Commander setup16"
  2. Click Next and then Next again to confirm the license agreement
  3. If you have a set of NT installation disks you want to modify check the "I already have NT setup floppies", if you don't and want the installation to create them leave the box unchecked. Click Next
  4. Insert your NT installation CD-ROM and click next
  5. Click Next at the next screen and then in the dialog box enter the location of your installation files, :\i386
  6. You will then be prompted to insert 3 blank formatted disks, and you should follow the on screen instructions. You put the disks in reverse order, so disk 3 first, then disk 2 and disk 1 last. This was so if you were installing you could just leave disk 1 in the machine once created and reboot, clever :-)
  7. Once the disks are created make sure disk 1 is in the disk drive and click Next on the ERD Commander window, it will alter the disk, then ask you to put in disk 2 and again alter a number of files. You do not have to put in disk 3 (this disk just contains drivers).

When the creation has completed you can insert disk 1 and reboot the machine to boot into ERD Commander. You will then be prompted to insert disk 2 then disk 3 and then finally disk 2 again.

There is a pause of about 30 seconds when it first displays the "Microsoft (R) Windows NT", don't worry, this is normal. You will then be shown a list of all the drives.

erdshot.gif (5430 bytes)

Pay attention to the drive letters, they may not match your usual drive assignments, this is because Windows NT grants letters on active partitions of each disk first, where as ERD Commander assigns them as it comes across them from floppy disk 0, hard disk 0 and then CDRom 0 onwards. For example if you had 2 harddisks, harddisk 0 and harddisk 1, with harddisk 0 having 2 partitions, Windows NT would assign the letters as

Harddisk 0, partition 1    c:
Harddisk 1, partition 1    d:
Harddisk 0, partition 2    e:

This is because active partitions are assigned drive letters first. ERD Commander would label the partitions as

Harddisk 0, partition 1    c:
Harddisk 0, partition 2    d:
Harddisk 1, partition 1    e:

This is not a problem, just be aware, don't panic that your files have disappeared :-)

You can now enter normal commands like dir, rename, copy etc. When you are finished Ctrl-Alt-Del does not work, just remove the ERD Commander disk and type exit.

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