Old v4 is no longer supported. But you can try: http://um11.eset.com/nod32 – though ESET stopped issuing v4 updates in 2020.
ESET allows business users to create a "Mirror Server." This is a computer on a local network that downloads updates from ESET and then distributes them to other computers on the network. This saves bandwidth.
If you absolutely cannot pay for ESET but want free, up-to-date protection, use ESET’s cloud scanner: