The article deals with the problem of ensuring information security of the Windows operating system and identifying promising security methods. This article identifies that the basic approach to operating system security is the "hardening of the operating system" process. The study presents statistics on the distribution of popular operating systems, namely Windows, Mac, Linux, Chrome, BSD. The analysis and classification of modern vulnerabilities of the operating system is made and the consequences of their action are given in the examples. These deficiencies can cause a computer system to intentionally violate the confidentiality, integrity and accessibility of information and the system as a whole. Based on the vulnerability analysis, the basic approaches and methods for the organization of protection of the operating system are determined. Standard approaches are discussed, namely the use of built-in security software, Active Directory security, and virtualization to deter attacks. Today, much attention is paid to cryptography and the principles of network, system, organizational and operational security, including risk analysis and disaster recovery, to ensure the security of the operating system. These approaches are basic and are a component of security in today's operating systems, but nowadays, using integrated approaches is more effective. A quick response to the violation of the integrity and accessibility of the operating system in combination with quenching, here are the main directions of development and improvement of the operating system. A rather new approach proposed in the article to protect Windows products is to use the Blockchain direction. It is currently used to validate digital certificates and can be said to have potential in other areas of operating system security. This paper shows examples of Blockchain implementation for certificate validation, taking into account some of the variations of validation. The examples are implemented in Python 3.0. The research of prospective methods and remedies of the operating system conducted in the article suggests that the use of system hardening is one of the effective and comprehensive approaches to providing security information, which will allow timely detection of vulnerabilities and timely response to violations of the basic properties of the operating system.