9e7742db_ime_manipulation___Heroes_Wiki__Theory
[Citations] Hiro's trip to the past appears to have actually changed past events from his perspective. (Six Months Ago) [Notes] + If Hiro's trip to the past to try and save Charlie were meant to have happened, then all of his former co-workers at the diner (to say nothing of Charlie herself) should have recognized Hiro when he came into the diner for the first time, six months after he had been working there. + From a writing stand-point, it doesn't make sense for Hiro and Isaac to have the powers that they do if they cannot use those powers to change future events. • However, although some events can be changed, it seems that others (such as Charlie's death at the hands of Sylar) are immutable. - But that changed, initially she was killed by Sylar, after Hiro went back in time, she refused to go to Japan because she had an inoperable aneurysm in her brain. He could change how she died, because that was the only reason for him going back in time. + Future Hiro's trip to the past allowed Claire to live five years longer following Sylar's first attempt to kill her. This shows that the timestream can be altered. (Five Years Gone) [Theory] 
There is no predestination in the world of Heroes.
Theory:Space-time manipulation - Heroes Wiki
Theory