Installation of operating system

A terminal device, comprising:

• a processor;
• and
• a machine-readable storage medium that stores machine-executable instructions, wherein by executing the machine-executable instructions, the processor is caused to:
• copy an installation boot file in an iso mirror file of a to-be-installed-operating system into a root directory of a removable storage device attached to the terminal device, wherein the iso mirror file is stored in the removable storage device;
• create an installation script file, wherein the installation script file comprises a pre-installation script used to indicate that the iso mirror file is to be mounted to a first folder of the terminal device;
• designate in the installation script file that a storage address of software installation packages in the iso mirror file is a storage address of the first folder;
• obtain an updated iso mirror file by adding the installation script file to the iso mirror file;
• obtain a startup disk by copying the updated iso mirror file into a hard disk, in which the operating system is to be installed, in the terminal device;
• and
• install the operating system in the hard disk, in which the operating system is to be installed, by using the startup disk and the installation boot file in the root directory of the removable storage device.