Since 2007 Microsoft word has used
a modern file compression system, the new system had different file format (DOCX)
rather than the old file format (DOC), people with old version of MS office
like 2003 they simple can not open or edit the DOCX files, because it is new
compression system is not included in MS office 2003.
Microsoft had released a compatibility
pack officially called Microsoft Office Compatibility Pack to overcome this problem;
By installing the Compatibility Pack in addition to Microsoft Office 2000, Office XP, or Office 2003, you will be able to open, edit, and save files using the file formats in newer versions of Word, Excel, and PowerPoint . The Compatibility Pack can also be used in conjunction with the Microsoft Office Word Viewer 2003, Excel Viewer 2003, and PowerPoint Viewer 2003 to view files saved in these new formats.
The compatibility pack can be
installed from Microsoft Download Center
