The exponential growth in users of computer over the years has impacted environment drastically. A primary concern of this paper is to study the transformation of computer state from grey to green. Green IT is basically referred to green computing. This paper shows how the emerging green technology reduces the negative impact of computing on the environment. The goal of green computing is simple: reduction in the use of harmful materials, maximizes energy efficiency and promotes recyclability. The idea is to ensure the least human impact on the environment.