Min version	XP	XP SP2	2003/XP64 SP1		Vista	Vista SP1	8 Pre RTM		8.1 Update 1	8.1	10 Pre RTM
Max version	XP SP1	2003/XP64	2003/XP64 SP2		7 SP1		8			10 Pre RTM	10 TH2
Architecture	x86	x86	x86	x64	x86	x64	x86	x64	x86	x64	x86	x64
x86 offset offset:bitpos	Field Name												x64 offset offset:bitpos
				void * PreviousBlockPrivateData		void * PreviousBlockPrivateData		void * PreviousBlockPrivateData		void * PreviousBlockPrivateData		struct _HEAP_UNPACKED_ENTRY UnpackedEntry	0x0000
						void * Reserved		void * Reserved		void * Reserved		void * PreviousBlockPrivateData	0x0000
						void * ReservedForAlignment		void * ReservedForAlignment		void * ReservedForAlignment		struct _HEAP_EXTENDED_ENTRY ExtendedEntry	0x0000
												void * Reserved	0x0000
												void * ReservedForAlignment	0x0000
0x0000	uint16_t Size										struct _HEAP_UNPACKED_ENTRY UnpackedEntry	uint16_t Size	0x0008
0x0000	void * volatile SubSegment	void * volatile SubSegmentCode		uint64_t CompactHeader	void * volatile SubSegmentCode	uint64_t CompactHeader	void * volatile SubSegmentCode	uint64_t CompactHeader	unsigned long SubSegmentCode		uint16_t Size	unsigned long SubSegmentCode	0x0008
0x0000					uint16_t FunctionIndex					uint64_t CompactHeader	unsigned long SubSegmentCode	uint64_t CompactHeader	0x0008
0x0000					unsigned long InterceptorValue					uint16_t FunctionIndex	struct _HEAP_EXTENDED_ENTRY ExtendedEntry	uint16_t FunctionIndex	0x0008
0x0000					unsigned long Code1					unsigned long InterceptorValue	uint16_t FunctionIndex	unsigned long InterceptorValue	0x0008
0x0000					uint64_t AgregateCode					unsigned long Code1	unsigned long InterceptorValue	unsigned long Code1	0x0008
0x0000										uint64_t AgregateCode	unsigned long Code1	uint64_t AgregateCode	0x0008
0x0000											uint64_t AgregateCode
0x0002	uint16_t PreviousSize				uint8_t Flags								0x000A
0x0002					uint16_t ContextValue								0x000A
0x0003					uint8_t SmallTagIndex								0x000B
0x0004	volatile uint8_t SegmentIndex	uint8_t SmallTagIndex			uint16_t PreviousSize								0x000C
0x0004					uint16_t UnusedBytesLength								0x000C
0x0004					uint16_t Code2		uint16_t Code2						0x000C
0x0004							unsigned long Code234						0x000C
0x0005	uint8_t Flags												0x000D
0x0006	uint8_t UnusedBytes				uint8_t SegmentOffset								0x000E
0x0006					uint8_t LFHFlags								0x000E
0x0006					uint8_t EntryOffset								0x000E
0x0006					uint8_t Code3								0x000E
0x0007	uint8_t SmallTagIndex	volatile uint8_t SegmentIndex	uint8_t SegmentIndex		uint8_t UnusedBytes								0x000F
0x0007					uint8_t ExtendedBlockSignature								0x000F
0x0007					uint8_t Code4								0x000F