star wars - Droid Memory Wipe

So in various stages of the books and movies, droid memory wipes are mentioned. This made me wonder why didn't the Jawa's wipe the memory of R2D2 and C3PO before they sold them? I would think it would be standard practice to prevent the exact issue that arouse that droids go off on their own because of the programming left by their former masters. Especially since they 'scavanged' the droids. If they bought them from a reputable dealer to resell, then that is different, but they technically stole them or at least didn't care who their owner was. One would think that to cover your tracks, you would wipe their memory before selling them.

Answer

Droid memory wipes are established in The New Rebellion as only affecting a droid's personal memories, not their hardwired memories. I'll paraphrase from memory here, as I don't have the book with me:

Security Droid: "When you get a memory wipe, do you need to re-learn all 6 million forms of communication?"

C-3PO: "Of course not, that's hard-wired in."

To use an analogy; when a human gets amnesia, they may forget who their spouse, parents and children are, but they usually remember their skills. A painter may not remember any of their paintings, but they will still remember how to paint. We don't actually know why this occurs, but I'm not a neurologist, I just need an example.

Droids in the Star Wars universe are also shown to be able to 'download' (my word) knowledge and skills which would be unaffected by memory wipes. Again in The New Rebellion, C-3PO passes the time when he's "bored" (that word is actually in the book, though I think Threepio is denying that he's bored) by downloading new languages into his hard-wired memory; this process is shown taking less time than a human learning a new language, but more than simply pressing a button and gaining instantaneous knowledge. It seems akin to the skill downloads in The Matrix.

That answers the question of what a memory-wipe actually entails. As to why the Jawas don't perform a memory-wipe, it is never actually stated in either the film or the novelisation. I don't recall even noticing it mentioned in any EU material either. My supposition would be that memory-wipes on droids require equipment that the Jawas, technological scavengers, simply don't have. We know the Lars family does not have the capacity to wipe droids' memories; they need to visit the nearby town of Anchorhead to do so.

C-3PO's memory is wiped in Revenge of the Sith, but that was a consular ship; a spaceship is likely far larger than a Jawa sand-crawler, with better technology, and a diplomatic vessel is itself quite likely to have specialised software and hardwire onboard for dealing with protocol and translation droids. This is a possible explanation of why they don't also wipe R2-D2's memory; the ship isn't set-up to deal with astromechs in the same way as it is protocol droids.