ESET provides a fully functional 30-day trial of its products, including ESET Smart Security Premium and NOD32 Antivirus, with no credit card required to start.
After the trial expires, you cannot simply re-register with a different email on the same computer. ESET tracks hardware IDs. However, you can install ESET on a different device (e.g., a family member's PC) for another 30 days. Eset Nod32 License Key Free - Search Shopping