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This is a small Windows command line tool that makes it possible to write disk images onto raw disks, like CF cards. While there is some protection against accidentally overwriting your hard disk, I CAN'T TAKE ANY RESPONSIBILITY FOR LOST DATA – YOU USE THIS PROGRAM ON YOUR OWN RISK.

If you prefer GUIs over command line applications, PhysGUI (written by Urs Zweifel) makes choosing the correct disk to write to easier (it can also identify disks more reliably than physdiskwrite).

Special considerations for Windows Vista/7/8

physdiskwrite works with Windows Vista/7/8, but you must make sure to run it as administrator (simply having admin rights isn't enough), or it won't find any disks. One way to do this is to create a shortcut to cmd.exe, then right-click it and select "run as administrator". Then you can launch physdiskwrite from the command prompt window that appears, and it should work fine.

If you get write errors shortly after physdiskwrite has begun writing to the target disk (usually after 65536 bytes), this may be caused by existing partitions on the disk. Use the Disk Management utility (right-click on the "Computer" icon on the desktop and select Manage, then navigate to Computer Management (Local)/Storage) to delete all partitions on the target disk before starting physdiskwrite.

If you are unable to delete all the partitions with the Disk Management utility, try the following procedure:

  1. Open a command window as admin ("cmd")
  2. Type "diskpart" and hit enter.
  3. Type "list disk" and hit enter to find out the number of your drive.
  4. Type "select disk X" (where you replace X with the number of your drive) and hit enter.
  5. Type "clean" and hit enter.


physdiskwrite 0.5.3 (38 KB)

physdiskwrite 0.5.3 + PhysGUI (188 KB) – needs .NET Framework 3.5

Change log

  • 0.5.3: fixed write error with some digitally signed images
  • 0.5.2: added new command line parameter -d to specify drive number (no confirmation prompts!)
  • 0.5.1: increased safety overwrite limit to 2 GB (instead of 800 MB); can still be overridden with -u
  • 0.5: support for digitally signed images; all of the first 32 physical disks are now probed (instead of aborting at the first error)
  • 0.4: model/serial number/firmware version and real C/H/S should now be reported (may not work with e.g. some USB CF adapters)
  • 0.3: a "-u" flag has been added to allow writing to disks > 800 MB (USE WITH CARE!)
  • 0.2: physdiskwrite can now automatically detect and decompress gzipped image files on-the-fly using the embedded zlib (


physdiskwrite [-u] [-d driveno] <image-file>

...or just simply drag-and-drop the image file onto the physdiskwrite.exe icon.

© 2003-2014 by Manuel Kasper <>. All rights reserved.