To obtain a handle identifying a specific device of a particular type, an appropriate function from the PHT_SERVER_CONFIG group must be used. For example, to obtain a handle identifying a floppy disk drive, the PrlSrvCfg_GetFloppyDisk function must be used; to obtain an optical disk drive handle, use the PrlSrvCfg_GetOpticalDisk (other functions are named similarly). Some of these functions obtain a handle of type PHT_HW_GENERIC_DEVICE described here. Others obtain a different handle specific to the device type. These other handles are derived from the PHT_HW_GENERIC_DEVICE handle and contain additional functions. For example, the PHT_HW_HARD_DISK handle is derived from PHT_HW_GENERIC_DEVICE and contains additional functions, such as functions for getting the disk partition information. All of the functions provided by the PHT_HW_GENERIC_DEVICE handle can also be used with derived handles, which means that a derived handle can be passed as a parameter to any of the functions described in this section. 

The following is the list of handles that are derived from PHT_HW_GENERIC_DEVICE: 

PHT_HW_HARD_DISK 

PHT_HW_HARD_DISK_PARTITION 

PHT_HW_NET_ADAPTER 

PHT_HW_GENERIC_PCI_DEVICE