GUID
typedef struct _GUID { DWORD Data1; WORD Data2; WORD Data3; BYTE Data4[8]; } GUID;
GUIDs identify objects such as interfaces, manager entry-point vectors (EPVs), and class objects.
A GUID is a 128-bit value consisting of one group of 8 hexadecimal digits, followed by three groups
of 4 hexadecimal digits each, followed by one group of 12 hexadecimal digits.
The following example shows the groupings of hexadecimal digits in a GUID.
origin.h