Very few people knew that Darth Vader and Anakin Skywalker were the same person up to his death in 5 ABY. Imperials who knew in the current canon: Sidious (emperor), Grand Moff Tarkin, all or most of the Inquisitors, Grand Admiral Thrawn, various clones in the early empire.
Darth Vader's true identity as Anakin Skywalker was a highly guarded secret, known only to a select few individuals including Palpatine, Obi-Wan Kenobi, Luke, Han, Leia, R2-D2, C-3PO, Master Yoda, Bail Organa, Ahsoka Tano, Darth Maul, Grand Moff Tarkin, Grand Admiral Thrawn, Jocasta Nu, Ferren Barr, Verla, Reva, ...
Both Yoda and Obi Wan knew from the holo revelations in the Jedi Temple that Anakin was now Darth Vader. For some reason, Obi Wan did not realize Vader had survived Mustafar. Nor had Obi Wan ever seen Vader's new visage.
R2-D2 was present when Padmé gave birth to Leia and Luke, so he knew Luke was Anakin's son – but what he didn't know was that Anakin became Darth Vader. In addition to that, Anakin's fall was surely a painful event in R2-D2's life, one that he definitely wouldn't like to remember or even talk about.
Though it sounds like he thinks Anakin is dead, he could also be viewing it as Obi-Wan does, where he believes Anakin died when Darth Vader was created. There's a hint that Owen knows Anakin was Darth Vader by the time of A New Hope.
DARTH VADER FINALLY FORGIVES OBI-WAN KENOBI(CANON) - Star Wars Comics Explained
Did Ben Kenobi know Vader was Anakin?
It was during his viewing of the hologram that Obi-Wan knew Darth Vader was Anakin. This is because Sidious said, “Henceforth, you shall be known as Darth… Vader”.
For other uses, see Lars (disambiguation). Owen Lars was a human male from the desert planet Tatooine who worked as a moisture farmer. He was the son of Aika and Cliegg Lars, and he became the stepbrother of Jedi Knight Anakin Skywalker when Cliegg married Anakin's mother, Shmi Skywalker.
C3PO was clearly created from some sort of kit or existing prototype since every protocol droid aside from coloring looks the same. He didn't recognize him because again, they all look the same & it was decades until he saw him again. There was no reason to believe he or R2 even existed anymore.
The sequence calls back to a similar scene in Revenge of the Sith, when Bail Organa orders Threepio's memory be erased to prevent him from sharing information about Anakin Skywalker's fall to the dark side.
The question being answered is: “Do R2D2 and C3PO know that Darth Vader is Anakin?” C-3PO? Definitely not. As many other have pointed out, C-3PO had his memory wiped at the end of Episode III, so it is almost certain that he does not know.
As Yoda considered such things to be dangerous, he thus deemed Anakin unfit for the life of a Jedi. Even after learning of Qui-Gon's death and Anakin's heroics during the Battle of Naboo, Yoda agreed to have Anakin join the Jedi Order but was against Anakin being made Obi-Wan's apprentice.
Both Yoda and Obi Wan knew from the holo revelations in the Jedi Temple that Anakin was now Darth Vader. For some reason, Obi Wan did not realize Vader had survived Mustafar.
Summary. Obi-Wan Kenobi believed Luke was the Chosen One, viewing him as the galaxy's last hope to bring balance to the Force and fulfill the prophecy. Maul, despite being Obi-Wan's enemy, also believed in Luke's status as the Chosen One, dying with the belief that Luke would avenge them in the future.
Leia's Force abilities and her lack of awareness of her true identity also contributed to Vader's inability to sense their familial connection. Vader's denial of Anakin Skywalker's legacy and his fear of getting hurt again prevented him from realizing the truth about his children until later in the original trilogy.
Darth Vader acts like he doesn't even know C-3PO or R2D2. They were with him since he was a child. He did everything he could to forget his past. Also, his plating had been replaced many times, and protocol droids all look very similar.
Since Obi-Wan and Anakin often fought together, Obi-Wan was friends with R2-D2 as well. This means that although R2-D2 might not have immediately recognized Obi-Wan on Tatooine due to his age, Obi-Wan should have recognized the droid.
She senses Anakin when she reaches out to the pilot — and Vader realizes that Ahsoka, his former Padawan, lives on. In Season 2, Episode 18, “Shroud of Darkness,” Ahsoka's guilt manifests as a vision of Anakin, who's angry with her for leaving him all those years ago.
Han Solo marries Princess Leia and they have three children: twins named Jacen and Jaina, and a younger son named Anakin. Luke reestablishes the Jedi Order, marries a non-movie (but fan favorite) redheaded Force-wielder named Mara Jade, and they have a son, Ben Skywalker (named in honor of Obi-Wan “Ben” Kenobi).
