Symptoms
When you open a Microsoft Office Word 2010 XML document, Microsoft Office Word 2007 XML document, or a Microsoft Office Word 2003 XML document in Microsoft Internet Explorer, Internet Explorer does not display the document by using the default Internet Explorer XML style sheet and does not display the XML code. Instead, Internet Explorer opens the XML document in an embedded Word window in Internet Explorer, or in a new Word window.
Cause
By default, Internet Explorer opens Word XML documents in an embedded Word window or in a new Word window.
Workaround
To create an XML document in Word that opens in Internet Explorer and that uses the Internet Explorer default XML style sheet (showing the XML code), change the document in Notepad to remove the following XML code from near the beginning of the document:
<?mso-application progid="Word.Document"?>
Status
This behavior is by design.