Free network environments software for windows

Let you send Messages over the network Network Message Sender application was designed to be a simple tool that will let you send messages over the network.

Network Traffic Generator is used to check what massive amounts of traffic of certain type will do to an intervening network Network Traffic Generator does not try to measure throughput or response times.
Network Traffic Generator has been made with the question in mind: If 100 clients does simultaneous TCP transfers for 2 days, will my router break? Or can I configure my firewall while 50 people are doing large TCP transfers through the device?
Who should use it?
Responsible software developers in a test environment that needs to know how their router/firewall/VPN holds up against continuous high traffic loads. You should be careful to use this tool only in environments where it will not affect the normal day to day operations of your coworkers.