In case you (like me) are unable to get the xdocdiffPlugin to work (looks like it does not work with the current WinMerge 2.12.4 version), you can use the "CompareMSExcelFiles.dll" plugin that is already included in WinMerge. It needs Excel installed on the same computer and is installed by default as long as the "Plugins" option was left checked in the Installer (select "Plugins->List..." to see if it is available).
To use this plugin, you must configure the following WinMerge settings:
- Select "Plugins -> Automatic Unpacking" to tell WinMerge to load the appropriate Unpacker plugin depending on the file extension.
- Goto "Edit -> Options", click on "Archive Support" and make sure "Detect archive type from file signature" is disabled, otherwise the modern Microsoft Office XML document filetypes (which are ZIP archives) will be unzipped automatically and thus not recognized by the Excel plugin.
- Restart WinMerge.
A similar plugin for MS Word documents is also included in WinMerge.