As part of my workflow I would like to clone the SD card first thing before I do anything.

Does anyone know of a good external USB drive cloner for Windows 7? Mac has this functionality natively (boohoo for Microsoft for not having this yet).

The idea is to clone it as read only, mount the cloned file as an external drive and then read it. (delete it after 90 days, but that's a different story) I would then copy the files and do anything from that cloned, mounted, drive.

That way I can then erase the SD card right after cloning to reuse it right away, but know I have all the info for a while in case I need it. A little extra paranoya, I know, but a healthy one. I've had it where I lost files on a move (don't know how, but it happened).


2 Answers 2


It sounds like MacOS is just creating a disk image file (.dmg I would guess) for the USB drive, which can then be mounted. I'm curious if you can actually clone an SD card, or just USB drives...SD/CF cards are usually treated differently than USB drives, and the MacOS clone feature is usually intended as a means of backing up literal external USB drives.

Windows 7 actually does have direct support for mountable drive images in .vhd (Virtual Hard Disk) format. You could create a VHD via the Windows 7 Disk Management tool, mount it, and copy the files from the memory card to your VHD (which, being a file, can be mounted, unmounted, copied for backup, etc.), and delete the VHD when you no longer need it. This would not be a 100% exact clone (although I suspect neither is the MacOS clone...its probably a new disk image with the contents of the external drive.) You could also use a backup tool like Acronis True Image to create USB drive clones, however it does not seem to support cloning SD/CF cards (at least, the version I have, 2011, does not.)

To create a VHD and copy the memory card contents to it, which would pretty much be as good as a MacOS DMG, do the following:

  • Right-click Computer, choose "Manage"
  • Expand the "Storage" node
  • Right-click "Disk Management"
  • Select "Create VHD"
  • Fill out the form
    • Size XYGb (i.e. 16Gb)
    • Fixed Size
  • Watch the status bar for progress
    • May take a few minutes...
    • Virtual disk will appear as an unallocated drive when done
  • Right-click "Disk" (should appear bright greenish-blue, unlike normal drives which are silver)
    • Select "Initialize"
      • Use MBR format for greatest compatibility
  • Right-click "Unallocated Volume" (should have a black "Unallocated" strip color)
    • "New Simple Volume..."
      • Next...
      • Next...
      • Pick a drive letter or mount to folder
      • Next...
      • NTFS or FAT32 (NTFS offers more features)
      • Add a Volume Label
      • Perform a quick format (Checked)
      • Next...
      • Finish
  • The drive should automatically mount, ready for use

Once you have a VHD, you can just drag-and-drop copy everything from a CF card to the VHD. In windows, cameras themselves show up as devices in Computer. You can open up the camera, and directly access the memory cards inside them, and just copy the DCIM and any other folders across to the VHD. If you have a card reader in your computer, the cards will usually show up as removable drives once you pop a memory card in. You can again just copy the DCIM and any other folders across to the VHD. Cameras usually have pretty fast interfaces, and copy pretty quick. Some memory card readers for computers, particularly cheap ones, are often limited to USB 1.1 speeds, so you might only get a few mb/s out of them. USB 2.0 ones will usually get you about 20mb/s. If you have the option, even for non UDMA-7 memory cards, picking up a $20 USB 3.0 PCI-e card and USB 3.0 CF/SD card reader will get you about 40-50mb/s (and significantly more, up to 150mb/s, on todays native UDMA-7/USB3 compatible CF cards.)

  • \$\begingroup\$ Ah, Windows. Everything is just a simple 18 step process away... \$\endgroup\$ May 5, 2012 at 10:04
  • \$\begingroup\$ I think Mac OS X's unix heritage is an advantage here: everything is a file, so hard drives, USB sticks, and memory cards are all presented as the same si abstraction. \$\endgroup\$
    – mattdm
    May 5, 2012 at 16:19
  • \$\begingroup\$ For that matter, ancient tape drives and future holographic memory too. :) \$\endgroup\$
    – mattdm
    May 5, 2012 at 16:25
  • \$\begingroup\$ @mattdm: True, however that does not change the need for a driver and abstraction layer to support ancient devices like tape drives or potential future devices like holographic memory. Also remember, current versions of Windows have their roots in DEC VMS (a DEC defector helped Microsoft write Windows NT way back in the day), which is one of the most robust, durable, and reliable operating systems the world has seen. Finally, from a semantic standpoint, both OS's are doing roughly the same thing...creating an image file and mounting it. MacOS just rolled a command for it. \$\endgroup\$
    – jrista
    May 5, 2012 at 17:36
  • \$\begingroup\$ It is also possible to reduce that "complexity"...which it really isn't, it takes about a minute to actually create a VHD and a couple seconds to initialize and format it. You can do pretty much everything in Windows with a command line using PowerShell these days. It wouldn't be hard to create a simple PowerShell script that created a new VHD, attached it, initialized it, formatted it, and copied the contents of your memory card to it, in a single activation. You could probably even make it activate on-drop, so you could simply drag the source memory card to an icon and clone it. \$\endgroup\$
    – jrista
    May 5, 2012 at 17:40

May I suggest Microsoft's SyncToy? While not nearly as seamless as doing it on a Mac or other Linux/BSD-based system, it is a fairly good piece of software that should assist you in your endeavors.

  • \$\begingroup\$ SyncToy copies the files and what I'm looking for is a bit by bit, sector by sector copy process. I'm currently using something similar to it: a commercial program called GoodSync. Also, looks like SyncToy has been discontinued (although I'm sure it still works fine). \$\endgroup\$ May 6, 2012 at 12:59

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