Zortam Media Studio FREE has all features like Zortam Media Studio PRO for 4 days. After 1 day you will need to purchase Zortam Media Studio PRO version in order to continue using PRO features (normalization, etc). We did it this way, because we wanted for our user to be able to see what we offer in PRO version before giving money for it. Once you enter license key for Zortam Mp3 Media Studio PRO you don’t need to download program again. All Zortam Mp3 Media Studio PRO options will be available for you! Of course Zortam Media Studio FREE doesn’t have any limitations and you can continue to use it as a freware program. For list of all FREE/PRO features go to: Zortam Mp3 Media Studio.