[g63marty]

Hello!
I just started using your plugin, thank you! It seems to work okay... after a few modifications.

On Windows 7 x64 using Caliber 0.8.65 and Open With plugin 1.5.4. Customize plugins.

The paths for the 64 bit executables and 32 bit executables are reversed.
32 bit programs should be %ProgramFiles(x86)% (usually C:\Program Files (x86)\...)
and 64 bit programs go in
%ProgramFiles% (usually C:\Program Files\...)

I know this is reversed from Windows 32 bit OSs which also uses %ProgramFiles% resulting in usually C:\Program Files\...

I'm not sure why Microsoft did this. Hopefully Calibre plugins are allowed to detect the OS bit count? Then you could populate the list accordingly. If not, another option is to test for the windows environment variables
IF %PROCESSOR_ARCHITECTURE% == x86 AND
%PROCESSOR_ARCHITEW6432% NOT DEFINED THEN
// OS is 32bit
ELSE
// OS is 64bit
END IF

Hope this helps!
MartyG