This bachelor thesis describes the concept of virtualization, which marked one of the biggest shifts in the IT world. Microsoft's approach to virtualization via Hyper-V solution is explained, while the theoretical part of the paper clarifies the logic in virtualization and its advantages. The disk, network, and process functions of the Hyper-V software is explained in detail, from technical and business point of view. Virtual networks, virtual switches, virtual disks, virtual memory, and virtual processors are shown. The theoretical part is concluded with high availability technologies, while each of the theoretical elements of this paper are accompanied by a practical scenario. The scenario is visually presented, explained in detail, and practically performed to understand the application of an individual element of the system as well as the entire system. Cluster of Hyper-V servers, domain controller, and data storage system were set up. Migrations of virtual machines and migrations of storage systems were performed. Backup system and automatic transfer of virtual machines to another server are provided in case of an error on the current server.