The word channel is easy to explain. Channel is a way of communicating with people or getting something done. Considering that communication can be a public process, a question will pop up that how can I secure my communication? That’s where the word secure comes into play. A combination of these two words will result in a concept which is absolutely crucial in Active Directory environment and that’s Secure Channel. The term “Secure Channel” can be defined as a way which authenticates the requester and also provide confidentiality and integrity of data sent across the way. In Windows Active Directory environments, secure channel provides an encrypted way of communication between clients and domain controllers. By clients I mean different editions of operating systems including client’s operating systems like Windows 7 or server operating systems which operate as Domain Controllers or member servers. You may ask me “You are keep saying that secure channel is important, but why?” To answer this question I would like to highlight the key role and responsibility of secure channel. In another word when there is no secure channel between a client and a domain controller there will be no completed Active Directory related tasks and as a matter of fact lack of secure channel existence or broken secure channel will fail everything related to domain. Group Policy and Computer authentication is case in point.