You can select "Continue As Demo" for a limited version that supports up to 2 client PCs indefinitely.

Given these significant risks, what are the best options for managing an internet cafe today?

: This specific version is dated (referenced as far back as 2007) and has known security vulnerabilities that could allow remote attackers to read files from the server. Default Credentials

Note that this software has known vulnerabilities (e.g., remote file read, CVE 2015). Ensure your network is secure and not exposed to the public internet.