If you wish to use dcraw.exe instead of the build in libraw library you will need to put the executable dcraw.exe
into the directory that contains the Magick.NET dll. The zip file ImageMagick-7.X.X-X-Q16-x86-windows.zip
that you can download from http://www.imagemagick.org/script/binary-releases.php#windows contains this file.
To force the use of dcraw the Format in the MagickReadSettings should be set to MagickFormat.Dcraw.
using (var image = new MagickImage("StillLife.CR2"))
{
image.Write("StillLife.jpg");
}