Block device drivers are generally stream interface drivers, and are therefore loaded in the same way as stream interface drivers. OEMs who include block device drivers with their Windows CE–based platforms include keys in the platform’s \Drivers\Builtin\ registry key so that the Device Manager loads the block device driver when the platform boots. Third-party block device drivers for PC Card block devices or similar removable hardware uses the \Drivers\PCMCIA\ registry key so that the Device Manager loads the driver when the relevant block device is connected to the system.