>>>Hello Sir,
>>>Thank You For Replying
>>>how the system date should be handled if system date is set back the product validity is extended
>>
>>I am not sure to understand this comment. If you extend the validity, you need to generate a new key.
>
>I haven't looked at your code but it sounds as if setting the computer system date to an earlier time will get round the check?

Everytime the application runs, the current date is saved (check CreateRegKeys). Then a validation is made in btnApplicationStatus_Click to check that the date is still valid.

As I wrote in the introduction of the article, nothing is 100% safe. You will always find someone to crack this mechanism. But you stop many from just copying your application completly for free. This mechanism can also be enhanced with your very own ideas.