A system for guest customization includes a processor and a data storage device. A service operating system is stored on the data storage device that, when executed by the processor, boots a virtual machine into maintenance mode. A response file creation module is stored on the storage device that, when executed by the processor, creates a response file. A customization agent is embedded within the service operating system that when executed by the processor on its startup, automatically performs customizations based on the response file including at least one of including adding or removing files within the data storage device and injecting main operating system or virtual machine agent startup scripts to complete customization once the virtual machine is rebooted into the main operating system.