typedef struct _DEVICE_FLAGS
{
     ULONG Failed: 1;
     ULONG ReadOnly: 1;
     ULONG Removable: 1;
     ULONG ConsoleIn: 1;
     ULONG ConsoleOut: 1;
     ULONG Input: 1;
     ULONG Output: 1;
} DEVICE_FLAGS, *PDEVICE_FLAGS;

Windows Vista Kernel Structures