The purpose of the article is to study methods of migration to other environments of information systems previously created in Microsoft Windows in the C# language. These environments either belong to the open class, or were developed directly in Russia. One of the main migration tools is the separation of systems into components. In this case, the transformation tasks of each component are solved separately. Methods of transformation of information systems functioning in an environment based on operating systems, database management tools, web tools, frameworks and libraries are considered. The main directions of preparation of the executive environment, the components of which are included in the register of Russian software, or provide open source codes, are highlighted. Operating systems that meet the given criteria are selected. Basically, these systems are founded on Linux kernel. Methods for configuring the Apache 2 web server and creating a virtual host are defined. A brief assessment of database migration methods was carried out. The issues of correcting the C# source code when changing the operating environment and methods of converting the source text when changing the ways of working with the graphical user interface are considered. The main problems during the transition to the new system and ways to solve them are shown. Taking into account the mandatory code correction required during the migration process and the development of a new graphical user interface, the transition from Windows to Linux is possible at real time-consuming costs. Using existing methods of migrating databases, web services and client applications allows you to complete the migration of information systems based on the C# language into environments that meet the criteria for import substitution.