It is highly recommended to perform the update over a wired Ethernet connection rather than Wi-Fi to prevent data corruption. Online upgrade by iVMS-4200 - Hikvision
If you have searched for you are likely on a mission to find the latest, most secure firmware via the official File Transfer Protocol (FTP) server. But why FTP? And where do you find these "new" files? hikvision ftp firmware new
To update your Hikvision device to the newest firmware, you can use several methods including the official FTP portal, the web interface, or automated tools. It is highly recommended to perform the update