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This is a small Windows NT/2000/XP command line tool that makes it possible to write disk images onto raw disks, like CF cards. It currently has a few rough edges, most notably in the selection of the device to be written – you have to decide which device is the right one by looking at the C/H/S values (though if the CF card was the last device to be connected to the system, it usually shows up as the last one in the list). Note that the C/H/S values may be incorrect for CF cards – looks like this is a bug in Windows. There is some protection against accidentally overwriting your hard disk, but then again, I CAN'T TAKE ANY RESPONSIBILITY FOR LOST DATA – YOU USE THIS PROGRAM ON YOUR OWN RISK.

Note to Windows Vista users: physdiskwrite works with Vista, 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.


physdiskwrite 0.5.1 (44 KB)

Change log

  • 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] <image-file>

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

2003-2007 by Manuel Kasper <>. All rights reserved.