Check available network ports in Windows

Question

Administrator is blocking some network ports, but some are left open (e.g. 80). Is there a portable utility to check what ports are blocked?

Using Windows 7 32-bit

Answer 1

ShieldsUP will rapidly scan all ports, from the Internet to your IP address.

Answer 2

I think you should try Nmap for Windows, it's a Unix network mapping tool ported to Windows.