Hello Zahra,
Thank you for your message.
Please note that the trial mode which is active for 30 days is different from the free license. To learn more please see
this page.
You can easily generate your free license key using
this form. The license key will be generated automatically and sent to your specified email address. Please note that you need to register Viewer with your free license key as described in
this tutorial.
Other Remote Utilities modules such as Host or Agent do not require registration.
Hope that helps.