Removing the program from your computer is not necessary. To turn a trial copy of Dr.Web into a licensed version, you need to purchase a license and register it. Right click on the Dr.Web icon in the system tray and select Register in the context menu. During registration you will need to choose the option Obtain a license key file with serial number. Once you have entered your serial number, a key file will be downloaded to your computer automatically. An Internet connection is required for registration.