A safe and non-polluted environment is the basic need of a living being. But today the situation is getting changed. Our environment is getting polluted day by day at a very high rate. The use of computing devices plays a vital role in harmfulness of environment. To reduce these harmful impacts the concept of Green Computing must be implemented. In this research paper we count some factors and find some issues and challenges which are barrier towards implementation of green computing. The main reason the awareness of a common user. If a common user is getting aware about the harmful impacts of use of computing devices over environment and takes some steps at own level to reduce electricity, the concept of green computing will be implemented.