Just a Win32 compilation of Alexandre Heitor Schmidt's gimp-image-subtraction-plugin. Works with Gimp v2.6
I only changed the name "gimp-plugin-template" to "image-subtraction" in all source files before compiling with msys/MinGW. I didn't include translations or help, which are empty files and wouldn't work even under Linux.
Filter is still found in [Image]/Filters/Misc/Image subtraction. Tell me whether you like a better place.
Just copy the executable named "image-subtraction.exe" into c:\Documents and Settings\username\.gimp-2.6\plug-ins\ or c:\Program Files\GIMP-2.0\lib\gimp\2.0\plug-ins\