A lot of useful tools to manage and monitor Windows:

“The Sysinternals web site was created in 1996 by Mark Russinovich  and Bryce Cogswell to host their advanced system utilities and technical information. Whether you’re an IT Pro or a developer, you’ll find Sysinternals utilities to help you manage, troubleshoot and diagnose your Windows systems and applications.”

I use TCP View a lot when I configure firewalls, the ports used by applications are often not well documented.