You can enstore an encrypted day counter in the registry that the program checks everytime it runs, as long as you use a relatively difficult key to crack, the majority of people will not be able to break it. This works best if you go off times used as oppose to if the date has been changed, because people can always wind the clock back before it ends. There are some great articles on CP about Registry keys and encryption. Please check out my articles: The ANZAC's articles