Remember: Database management is about trust and accuracy. If you cannot trust the software license, you cannot trust the tool with your data. Pay for the software, or switch to open source—but never risk your entire database on a cracked serial code from a shady website.
Before providing any guidance, it is crucial to state: Using unauthorized serial codes violates software copyright laws (Digital Millennium Copyright Act in the US, EUCD in Europe) and can expose users to malware risks from keygen trojans.