You installed Office 2003 in your machine. You do not have Office 2007 on your machine.
Now your friend mailed to you a file which is created by office 2007.
What will you do?
How will you open Office 2007 based files (i.e., .docx, .xlsx, .pptx) in office 2003?
Here is the procedure to do:
1) Download "Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats" from Microsoft.
2) Install it on your machine.
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 new to Word, Excel, and PowerPoint 2007.
One more way: