It is critical to understand the difference between the and the Virus Signature Database .
For "air-gapped" computers (machines that never touch the internet), you cannot rely solely on the installer. You would need to manually download the virus signature update files (usually available as .nup files via the ESET update downloader tool), but this is a complex process usually reserved for enterprise environments.
ESET offers one of the most IT-friendly offline installers on the market, balancing file size with full feature inclusion.
Before diving into the "how," it is worth understanding the "why" for offline installations: