How to know what process is using which port in windows

I believe this is going to be a very helpful post to most of the readers. So many times I need to know about this. This is a great tip to resolve so many problems. So, it is one of my hot tips for identifying the problems.

We usually install third party software like Skype, TeamViewer etc. in the windows OS, then they will default take some port numbers available. Then there are chances they will create some problem as explained below. [This is why we need to take care of installing software on the servers or production machines. We should install if and only if we really need them. :)] Below is the complete scenario.