Table of Contents

# Installation and Run

System Requirements Activation Settings Languages

Attention! If a device has physical problems (input-output errors, slow performance, etc.) it is recommended to contact specialists - see Working with Failing Drives.

If the device is not accessible in macOS see disk access in macOS.

If the device has incorrect size see Wrong Drive Size.

Attention! Do not write anything to the disk containing lost data. Recover data to a different disk, as well load operating system, run the software from a different disk, otherwise the data may be erased irrevocably.

It is highly recommended to at least unmount the drive containing the lost data (remove the drive letter in Windows) or use a special operating system (OS environment) with minimal access to the drive.

## OS Environment for Data Recovery

It is highly recommended to work in a system with minimal disk access (especially in write mode). You can use bootable LiveCD/LiveUSB disks based on Linux or special environment like WinFE based on Windows, where disk access is minimized. Or create a DOS bootable disk to clone disks available in IDE mode.

For the most compliance with such environment it is recommended to turn off the "fast boot" option and turn on the "USB legacy" mode in your BIOS/UEFI. To boot from the Live disk you may also need to turn off Secure Boot and UEFI mode (switch to Legacy BIOS mode).

## Installation

To install/reinstall and run the program just extract the entire software package into a single directory (it can be on a removable media) and run dmde.exe or dmde. Updates are performed in the same way.

You need Administrator / Superuser priveleges to access devices in Windows NT+, Linux, macOS. To run the software without Administrator priveleges add the parameter notadmin=1 to the file dmde.ini.

For more information, see the "Operating Systems" below (Windows / Linux / MacOS / DOS).

To uninstall the software just remove the extracted files and directories.

## Operating Systems

### Windows Vista/7/higher

If SmartScreen prompts, click "More Info" and confirm that you want to run the software.
To run the program as an administrator, right-click the application icon, use the appropriate menu command, and confirm the UAC elevation request.
Attention! To work with drives larger than 2TB the most recent versions of controller drivers must be installed.

### Windows 2K/XP

To use the program you should login as an Administrator.
Attention! For drives with a capacity of 128 GB or more, ServicePack updates must be installed (Windows 2K SP4 or Windows XP SP2) and LBA48 support must be enabed in the system registry (manually for Windows 2K, and it is enabled by default in Windows XP SP2). Windows 2K/XP does not support drives larger than 2TB with the exception of XP-compatible USB-drives/boxes.

### Windows 98/ME

Attention! Without special patches Windows 9x/ME handles 128GB and larger drives incorrectly.
To avoid the problem reload computer in MS-DOS mode and use DMDE for DOS to access such drives via BIOS or ATA-interface or load another OS.

### Linux

For information on how to run software as a root user, see your operating system documentation. Typically, this involves going to Terminal or running a Terminal emulator (Konsole, Gnome-terminal, etc.), going to the program's folder, and running sudo ./dmde, or first logging in as root with su and then running /.dmde.

You may also need to set execution permission for the file dmde (chmod 755 ./dmde). To run 32-bit software versions on 64-bit operating systems you may have to install additional 32-bit shared libraries (e.g., run sudo apt-get install libc6-i386 in Ubuntu to install libc6-i386 package).

### MacOS

Since modern versions of macOS try to prevent direct disk access and are less capable of handling faulty disks, it is recommended to use other operating systems. If you don't have another PC or can't connect your drive to it, you can try creating and booting Ubuntu LiveUSB by following the instruction.

If you cannot access disk in macOS you can try to unmount the disk using the system's Disk Utility to gain access. Another option is to create the disk image to a file using the Disk Utility and then work with the disk image.

If macOS blocks the application you can use Control-Click / Right-Click Menu - Open or go to System Preferences, choose Security & Privacy and click "Open anyway" for the blocked application: Safely open apps on your Mac.

On macOS the program can be launched directly from the .dmg package. However, in this case, it will not be able to save its settings in its folder. The same can happen with an extracted application, since macOS launches applications obtained from the Internet from a randomized directory. In this case, the program will offer to save the settings and keys in the default application support directory of the current user.

To enable portable launch (to store settings directly in the program folder), you can copy and paste all application files from the .dmg package, including the dmde.ini file, to a separate folder. If you first extracted the files (rather then copy-pasting then), you also need to remove the quarantine attribute by using the Terminal command
xattr -r -d com.apple.quarantine dmde.app
or just
xattr -cr dmde.app

It is also possible to run the console version of the software as root user from a terminal, see Linux instructions above. Since console applications on macOS cannot be signed, you can use the following command in Terminal to avoid restrictions when running an application downloaded from the internet:
xattr -cr package-name.dmg

### DOS

If there are problems with video ouput you may need to change the value of the parameter biosoutput=0 in the file dmde.ini into: biosoutput=1

If an error occurs when starting the software, there may be a problem with an extended memory manager. Try using the old memory manager by running the batch file dmde_dpo.bat however less memory will be available.

You may use DMDE on a regular partition supported by DOS or use DOS bootable disk. This can be helpful when there are problems using specific disk. SATA disks must be switched to IDE-compatible mode in BIOS settings for direct ATA-access. SCSI, USB, and other devices can be accessed via special DOS drivers or using BIOS functions if they are supported.

Some files for creating DOS boot disks are available on the software site in the section Additional Downloads.

#### Bootable Floppy

To create bootable floppy download and unpack FDD image. You may use the function Copy Sectors to write the image to a floppy disk. Use the image as a source file and fdd as a destination device. ISO images for bootable CD may also be created on the base of boot FDD images with the help of different software.

#### DOS Bootable Disk

Loading from the specific disk must be supported by BIOS (see BIOS boot menu). To create bootable USB/HDD you need a freshly formatted primary FAT16/FAT32 partition on the disk. Non-standard disks/partitions are not supported (non-MBR, 3TB+, etc.).

0. For the most compatibility optionally first zero out the disk, then initialize disk as MBR and create and format a primary FAT partition using standard OS means (Windows Disk management).
1. Download the FreeDOS Package (the site section "Additional downloads") and extract all package files directly to the root directory of the FAT partition.
2. Open the disk as physical device in DMDE and use the command Write Boot Sectors... in the Partitions menu to make the device bootable (specify the root directory on the disk as a source of boot sectors upon the subsequent request). Apply changes and close DMDE.
3. Download DMDE for DOS and unpack into the FAT partition.
4. Use BIOS boot menu / BIOS setup to boot from the specified disk. On modern UEFI systems you may need to enable BIOS legacy mode, turn off secure boot option, switch USB and other devices to legacy modes.

## Wrong Drive Size

Do not work with a disk which size is detected incorrectly. For HDD drives or incorrectly connected devices it is sometimes possible to resolve size related issues by yourself - see the guide from an external source.

- Capacity limit jumper is not set correctly (device size is limited to 32GB)
- HPA is applied incorrectly. The device size is usually reduced by 1TB or so (typical for some GIGABYTE motherboards). Try software: HDD Capacity Restore Tool (Windows), hdparm (Linux), HDAT2, MHDD, Victoria (DOS)
- The OS does not support large disks - see below
- Incorrect drivers for SATA/USB controller (no correct support for 3TB+). Device size is tipically detected as 2.2TB less. Update drivers
- The USB enclosure / other adapter does not correctly support 3TB+. Replace the adapter or attach the device directly
- The disk is detected as zero size or the SD card or USB drive is detected as tiny size: the device is not accessible, it is recommended to contact specialists