Since the new PC, World of Warcraft had the tendency to crash frequently and at really annoying times (like in the middle of a fight, resulting in my death).
Since it crashed with an access violation error on the memory, i decided to run some memory tests. And indeed, one of the 2 RAM units was severely damaged, and thus I had to return it to the store.
I got a brand new one, and already installed the game, this time without any installation errors. I yet have to play it for a longer duration, but I'm confident the memory was the root of all my crashing problems.