You could use a macro

Sub SaveAllAsHTML()
Dim strFileName As String
Dim strDocName As String
Dim strPath As String
Dim oDoc As Document
Dim fDialog As FileDialog
Set fDialog = Application.FileDialog(msoFileDialogFolderPicker)

With fDialog
   .Title = "Select folder and click OK"
   .AllowMultiSelect = False
   .InitialView = msoFileDialogViewList
   If .Show <> -1 Then
       MsgBox "Cancelled By User", , "List Folder Contents"
       Exit Sub
   End If
   strPath = fDialog.SelectedItems.Item(1)
   If Right(strPath, 1) <> "\" Then strPath = strPath + "\"
End With

If Documents.Count > 0 Then
   Documents.Close SaveChanges:=wdPromptToSaveChanges
End If
If Left(strPath, 1) = Chr(34) Then
   strPath = Mid(strPath, 2, Len(strPath) - 2)
End If
strFileName = Dir$(strPath & "*.doc")

While Len(strFileName) <> 0
Set oDoc = Documents.Open(strPath & strFileName)

   strDocName = ActiveDocument.FullName
   intPos = InStrRev(strDocName, ".")
   strDocName = Left(strDocName, intPos - 1)
   strDocName = strDocName & ".htm"
   oDoc.SaveAs FileName:=strDocName, _
       FileFormat:=wdFormatHTML
   oDoc.Close SaveChanges:=wdDoNotSaveChanges
   strFileName = Dir$()
Wend
End Sub

http://www.gmayor.com/installing_macro.htm