Documents created in Word 97-2003 are saved with the file extension .doc, while those created in Microsoft Word 2010 are saved with a .docx file extension. The convert command is used to clear the compatibility options and convert earlier document to the Word 2010 file type.
1. Open document in Word 2010
2. Click the [File] tab
3. Click the [Info] command button
4. Click [Convert], the following prompt will be displayed:
5. Click OK
The document is now upgraded to a Word 2010 format.