In todays rapidly changing scenario, individuals and organizations are relying heavily on automated computer systems to store, retrieve, process and exchange information. Organizations uses the information stored on these systems to conduct vital business operations. Therefore, organizations need to protect the information from unauthorized access and potential destruction. Earlier, an organization, computer system was developed, used and maintained in isolation from other areas of business. The rapid growth and widespread use of electronic data processing and electronic business conducted through the Internet, along with numerous occurrences of international terrorism, fueled the need for better methods of protecting the computers and the information they store, process and transmit. IT managers, Network Administrators and Database Administrators face increasing challenges of managing and protecting information and network resources from unauthorized access. So to preserve data securely every IT user must know the benefits and losses about the computer security. Which are the different threats to computer data and which are the different security controls and policies required to maintain data security? In view of the above, the present research work entitled �A Critical Study of Data Security in Selected Co-Operative Units of Warana Udyog Samuha� has come up for further in-depth study.