Try to set the Document Encoding to UTF8 and WdSaveFormat with wdFormatDocument97 instead of wdFormatRTF.
'Convert the HTML File to Word document.
Dim word As Microsoft.Office.Interop.Word._Application = New Microsoft.Office.Interop.Word.Application
Dim wordDoc As Microsoft.Office.Interop.Word.Document = word.Documents.Open(FileName:=htmlFilePath, ReadOnly:=False)
wordDoc.Encoding = System.Text.Encoding.UTF8
wordDoc.SaveAs(FileName:=filepaths & "\" & "Export.doc", FileFormat:=Microsoft.Office.Interop.Word.WdSaveFormat.wdFormatDocument97)
CType(wordDoc, Microsoft.Office.Interop.Word.Document).Close()
CType(word, Microsoft.Office.Interop.Word.Application).Quit()
File.Delete(htmlFilePath)
