Beginning with Office 2007, Microsoft unveiled a new file format, called Open XML, which uses the .docx extensionbut isn't compatible with older versions of Office without some assistance. Here ...

While admittedly it’s not as simple as it is on macOS to open a .docx file using Pages, here's how to open, edit and even re-export .pages files on a Windows PC.

Click "File" in Pages '09 and then choose "Open" from the menu. Select the DOCX document using the built-in file browser and then click "Open" to open it in Pages.