A method of booting up update software in a writable memory area of a boot sector of a programmable control device of a vehicle is provided. The method Provides a boot-up software that can be booted up in a writable memory area of the programmable control device which is situated outside the boot sector. The boot-up software is capable of controlling, in the control device, the installation of the update software in the writable memory area of the boot sector, booting up the boot-up software and the update software in the writable memory area situated outside the boot sector, and executing the boot-up software in the control device in order to install the update software in the writable memory area of the boot sector.