Need to delete duplicate of a column B based on column A and keep Column B if unique value

Hi EP, welcome to the forum! With so many records, the sort is CRITICAL as it reduces the need for in-formula comparisons.
Paste this in D2 and copy down:

=IF($B2=$B1,IF($C2=$C1,D1,""),$B2)

Now select column D, press CTRL+C, then Paste VALUES. Finally, sort on column D to move the Blanks to the bottom, then delete them.

Row\Col	A	B	C	D
1	#	Code	Time Stamp	New
2	1	1111	12 Aug 2017 19:45:43:20	1111
3	2	1111	12 Aug 2017 19:45:43:20	1111
4	3	1111	12 Aug 2017 19:45:43:20	1111
5	4	1111	12 Aug 2017 09:45:48:20
6	5	1111	12 Aug 2017 09:45:48:20
7	6	2222	17 Aug 2017 21:25:43:20	2222
8	7	2222	17 Aug 2017 21:25:43:20	2222
9	8	2222	11 Aug 2017 21:25:43:22
10	9	3333	20 Aug 2017 19:45:43:20	3333
11	10	3333	20 Aug 2017 19:45:43:20	3333
12	11	3333	20 Aug 2017 19:45:43:20	3333
13	12	3333	20 Aug 2017 19:45:43:20	3333
14	13	3333	20 Aug 2017 19:45:43:20	3333
15	14	4444	25 Aug 2017 19:45:43:20	4444
16	15	4444	21 Aug 2017 19:45:43:20

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