When you purchase a license for an ESET product, you will receive an email from ESET containing your ESET-issued Username, Password, and License Key, along with other important license information. This email will be delivered to the email address used at the time of purchase.
Depending on the version of your ESET product, an ESET-issued Username and Password or License Key is used to activate your product. Once activated, your product is able to receive the latest virus signature database and program component updates.