I have installed Moodle on Windows 10. How can I open it on another system in LAN?
If the URL is http://localhost/something, then you can't. Make it respond to http://ip.address/something. This is mainly a operating system (network) and the web server configuration issue. Note that $CFG->wwwroot in the config.php must match. Once you get that going, there is a good chance that you can visit the same address from other machines, provided you've managed to allow that in the Windows 10 firewall. If you don't know how, then disable the firewall entirely.