Nmap is an open source network scanning software that allows you to discover devices and services on a network.
It is generally used by network administrators and security professionals (pentesters) to identify vulnerabilities in a network.
The Windows version is easy to install and has a graphical user interface (GUI) that makes it easy to perform network scans.
Nmap supports a variety of scanning techniques such as ping scanning, TCP and UDP port scanning, and detection of running services.
It also offers advanced features such as remote operating system detection, traceroute and firewall detection.