How about something like this? I think you need to pass the document to the SaveAsDoc function.
Code:
Sub SaveAsDoc(d As Document)
Dim newfile As String
If InStrRev(d.Name, ".html") > 0 Then
newfile = Replace(d, ".html", ".doc")
ElseIf InStrRev(d.Name, ".htm") > 0 Then
newfile = Replace(d, ".htm", ".doc")
End If
d.SaveAs2 newfile, FileFormat:=wdFormatDocument97
End Sub
Sub ConvertHTMLtoDOC()
Dim file
Dim path As String
path = "C:\scratch\"
file = Dir(path & "*.htm*")
Do While file <> ""
Dim d As Document
Set d = Documents.Open(file)
Call SaveAsDoc(d)
d.Close
file = Dir()
Loop
End Sub