Show usable ProgIDs for win32com

This example shows you the available ProgIDs of the Windows applications which are installed and ahould be usable  with win32com. My problem is, that most of the ProgIDs are shown, but not all ?!

import win32com.client
strComputer = "."
objWMIService = win32com.client.Dispatch("WbemScripting.SWbemLocator")
objSWbemServices = objWMIService.ConnectServer(strComputer,"root\cimv2")
colItems = objSWbemServices.ExecQuery("Select * from Win32_ProgIDSpecification")
for objItem in colItems:
    print "Caption: ", objItem.Caption
    print "Check ID: ", objItem.CheckID
    print "Check Mode: ", objItem.CheckMode
    print "Description: ", objItem.Description
    print "Name: ", objItem.Name
    print "Parent: ", objItem.Parent
    print "ProgID: ", objItem.ProgID
    print "Software Element ID: ", objItem.SoftwareElementID
    print "Software Element State: ", objItem.SoftwareElementState
    print "Target Operating System: ", objItem.TargetOperatingSystem
    print "Version: ", objItem.Version
    print "-------------------------------------------------------------------\n"