The invention relates to the installation of an operating system at a local computer connected or connectable to a remote management computer. To do this a standard operating system is provided on a storage medium at the local computer. Then a modular definition of an operating system model, defining a customised configuration of the standard operating system, is supplied from a memory at the management computer to the local computer. The standard installation of the operating system to a memory of the local computer is performed using the standard operating system on the storage medium and, in addition, this is customized using the model. The use of a modular definition of a model of a customized operating system installation facilitates the maintenance of the customized installation procedure.