'A friend has developed a web site...' - no he has not. He created a 'MS Word' document and saved it as a 'Single File Web Page'.
'... so what can I tell him to do to remedy this problem?' - he is the commercial web site developer, not you. He should know how to remedy his problems. That said, tell 'him' to obtain a freeware, shareware, or commercial HTML editor.
'Is it his programing or something I need to do on my end?' - you have to do nothing, he needs to exam, understand, and correct his code.
Hint: ''<?xml:namespace prefix = v />, '<?xml:namespace prefix = o />', and '<?xml:namespace prefix = w />' are the incompatiblities.
'If it is something he needs to fix will you please tell him? He has a link to contact him on his website.' - he, not you - should be investigating and correcting the imperfections of his web page generating skills, and / or understanding of how 'MS Word' creates web page HTML.
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He saved the 'MS Word' document as a 'Single File Web Page', which created an embedded file. This is typically for e-Mail'ing the web page, and on the Windoze platform - supported by Internet Explorer 4.0 and later. Not on the Macintosh platform.
Tell him to save the 'MS Word' document as a 'Web Page'. This will create a 'x.htm' file, as well as - a 'x_files' folder of 'filelist.xmll' and related graphic files (where 'x' is the name of the saved 'MS Word' document).
'He' can learn about 'Singe File Web Page' by entering such text into 'MS Word's 'Help' window. (as you can also, on a Mac).