There are many alternatives to Nmap for Windows if you are looking for a replacement. The best Windows alternative is Fing, which is free. If that doesn't suit you, our users have ranked more than 25 alternatives to Nmap and many of them are available for Windows so hopefully you can find a suitable replacement. Other interesting Windows alternatives to Nmap are Angry IP Scanner (Free, Open Source), Zenmap (Free, Open Source), Advanced IP Scanner (Free) and Advanced Port Scanner (Free).
NmapSi4 is a complete Qt4-based Gui with the design goals to provide a complete nmap interface for Users, in order to menage all option of this power security net scanner and search services vulnerability.
The IPPINGER is an application for checking a host or multiple hosts periodically. It can check IPs, websites and also ports (if are open). It can be configured to notify by email or Windows Notification when a host is down.
NetCrunch Tools is a completely free toolkit for network professionals, featuring Ping, Traceroute, Wake OnLAN, DNS Info, Who Is, Ping Scanner, Service Scanner, Open TCP Port Scanner, SNMP Scanner, DNS Audit and Mac Resolver in one.
Rumble is a network discovery platform that enumerates the network topology, identifies devices, and creates an asset inventory. Rumble runs discovery scans via a locally installed agent or using the standalone Rumble Scanner on the command-line.