A method and apparatus for installing an operating system. Data of a first operation system is acquired, and the first operation system is installed and launched according to the data of the first operation system. Configuration information of the first operation system is modified to add installation related information of a second operation system, after the first operation system is launched. Data of the second operation system is acquired according to the installation related information of the second operation system, and the second operation system is installed to replace the first operation system according to the data of the second operation system.