Information systems has been come into human life, since the second part of twentieth century as a result of rapid technological developments and has begun to affect every area of life. Today; a great many of information related with both private and business life has been recorded and saved in information systems. In the past, very few people has a right of access to information systems. Today without any need for special expertness, everybody can access easily. Even unauthorized people can access to information systems which belong to other people in unlawful ways. For this reason, protection of information systems and information takes part in that system against unauthorized accesses has been gained great importance in terms of criminal law. In Turkish Criminal Code No. 5237 art. 243/1 accessing information system illegal has been prepared as a crime. On the other hand, what should be understood from information systems notion,what should be considered in this notion should be discussed. Discussion is important in terms of identification of punished and unpunished acts. In Turkish criminal law discipline, “unauthorized access to IT systems” has been considered rather on personal computers and information systems but, problems related with computers assigned to public and private sector employees and information systems has been neglected. To our knowledge, computers assigned to public and private sector employees should be considered separately in terms of unauthorized access to IT systems. Because, if public and private sector employees use computer which belongs to other personnel constitutes a crime or not is an important question that should be answered. Studies done for answering this question will lead the way to application. This study has been done for the purpose of if computers assigned to public and private sector employees should be assessed separately or not in terms of unauthorized access to IT systems; giving an answer to a question related with if there is a difference between personal computers and computers which are assigned for the purpose of doing community service or not, in terms of commission of offence and scrutinizing problems related with the subject. In the study, were examined in detail. But, with the Code No. 6698 dated 24.03.2016, which was added as a fourth paragraph art. 243, is excluded from the scope of the work, because it is an independent offense, even though it is regulated in the same Article.