Essential NetTools is a pack of tools for network administrators, computer security professionals, and for all the people who want to have a better understanding of how their computers work and how secure they are.

Great software. Shows detailed information about what your PC, running applications and background processes are doing. The tools come with a fair range of configurable options. Potentially a very useful application for building ACL's; as well as helping debug basic windows-type network/application problems. (you'd want a sniffer and an application developer to find more serious problems.) The interface is sleek, and easy to use. The built-in help gives good information on each tool and how to use it, but doesn't explain all the configuration options available.

Source: download.com