However, it is highly recommended to download the latest updates from Microsoft before you proceed to installing the compatibility pack. You can have Microsoft Office Compatibility Pack completely operational in less than a minute. Microsoft Office Compatibility Pack can patch early Office versions to make them compatible with files that were created with Office 2007, specifically DOCX documents, XLSX files and so on. Fortunately, you can provide a solution for this issue as well. This has been an issue since the release of MS Office 2007, especially for inexperienced users, who don't pay much attention to file formats.
If someone asks you over the phone why they can't open a document with MS Word, there can be only one answer you can provide: they are trying to open a DOCX file with an older Word version.