With the development of digital and information technologies, electronic theft, forgery of documents, etc. began to appear. Criminals have mastered a new space and cause damage, stealing data not only from commercial organizations, for example, Borovikov systems, but also personal files of the average user. The service of protecting information on a PC has already become popular. Users are increasingly becoming aware of the importance of technical security of data stored on electronic devices. Not all users can take care of the security of private files and configure protection on their PC. Therefore, the article is devoted to the issue of quantifying the information security indicator on a computer, depending on the impact on the information structure of various types of internal and external threats (reflects: identification and authentication of users, control of data integrity and authenticity, data backup, delimitation of access to information, Firewall operation (packet filter), audit, antivirus, failures of software and hardware components, speed of information leakage, the effect of the amount of information on their leakage, the effect of information security threats from the loss of trust between users, the effect of the size of the computer system on security, the impact of computer security on information leakage). To solve the specified tasks, a mathematical model of information protection in a PC based on a system of differential equations was developed and solutions were simulated in the MatLab system. Three options for solving the equation near the steady state of the system were considered (a more visual analysis of the system’s behavior was performed, with a transition from the differential form of the equations to a discrete one and modeling of a certain interval of the system’s existence), it was concluded that, based on the conditions of the ratio of dissipation and the natural frequency of fluctuations of the magnitude, damping the latter up to a certain value is carried out periodically, with a decaying amplitude, or according to an exponentially decaying law. Taking into account the impact of the specified parameters on information protection and the possibility of determining a quantitative indicator of protection, PC users will be able to independently assess the impact of each component of threats and make adequate protection decisions.