1. A method for a computer or information appliance to securely manage file updates, the method comprising the computer-executed steps of: a first processing environment retrieving a bootable disk image for a second processing environment from one of a plurality of data storages in the first processing environment; the first processing environment sending such bootable disk image to the second processing environment through a first interface between the first and second processing environments; the second processing environment storing the bootable disk image in a temporary data store in the second processing environment; then following the completion of the booting of the second processing environment, the first processing environment limiting file requests by the second processing environment to the plurality of data storages through the first interface to only those requests required to complete booting; and then the first processing environment managing non-booting requests by the second processing environment to the plurality of data storages through a second interface between the first and second processing environments.