Starting with HelpNDoc 7, *.docx documents are imported by HelpNDoc without the need for any third-party software.

For earlier versions, the free "Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats" must be installed on the system in order to import Microsoft Word *.doc or *.docx files. It is automatically installed with some older versions of Microsoft Office but not with the latest versions. It can be downloaded from Microsoft's web-site at https://www.helpndoc.com/downloads/office-converter/FileFormatConverters.exe