His first attempt is saving Claire via Peter. It works, but history still repeats itself with minor changes. Peter blows up NY, and somehow Sylar fakes his death. He still kills Nathan, but doesn't get Claire until later...at that point he seems like he was going to take over the world.
The cool thing is - is that the younger 'hiro' mentioned about Sylars' capture and that there was a way to defeat him now because of that. I feel his capture only happened because of the cheerleader being saved and thus the slightly different history happened as a result.
I wonder if (after looking at previews) Hiro will go back again and try to kill Sylar at HRG's holding cell. What if Hiro went all the way back to before Mohinder's fathers' critical rejection interview with Sylar? I know it was not in the comic book but what if Hiro killed Sylar before he got his powers OR talked Mohinder's father into accepting Sylars' ability so he wouldn't go psycho from the rejection?
I guess Hiro can't go back to before Sylar got any of his powers and kill him because this whole series could have been over months ago . --though he technically has the ability to do so.
I think it would take future Hiro to pull something like that off. Present Hiro still doesn't have a real good handle on his abilities. Even if Mohinder's father accepted Sylar, I still don't believe he is really stable. I think we will learn more about Sylar next week, especially when he goes to see his mother. Even when he was rejected, he still had a power...he could see how other peoples powers worked, and through killing them, could acquire those powers.
From the previews, it looks like Hiro does try to kill Sylar. I'm thinking that Hiro freezes him, but somehow, Sylar can either fight it off or is immune to it.