Heroes fans!?

In the alternate 5 year future how come Sylar has regeneration? Alternate future Hiro asks to save the cheerleader because in there timeline Sylar wasn't stopped by Peter and supposedly kills Claire. So he regenerates from Hiro's fatal blow, but Caire is alive in the alternate future. Unless he finds someone else who can heal, but he seems pretty keen on getting her abillities in the alternate future. Any other ideas?

The alternate future we see isn't the same, it's complicated. There are four timelines, not two. The one we end the season with (the bomb doesn't explode) and the alternate future had different events.

1. Hiro travels five weeks into the future and appears in New York. Everybody thinks he is missing. The explosion occurs in the middle of the day on November 8th, Ando isn't killed as he never left Japan but Claire was. Hiro teleports back to October 2nd just as the explosion consumes the city, ending the first timeline and starting an altered timeline, the second timeline. That is how each timeline is created.

2. Hiro returns to the past and takes Ando with him to America, (this is the timeline we see for the first few episodes.) Nobody is there to warn Hiro or Peter about Sylar so nobody comes to Claire's aid, so she is killed and Sylar gets the ability to regenerate.
Events occur similar to what we see, with the exception that Ted, Matt and Bennett never go to New York. Peter never meets Ted and never absorbs his nuclear ability, but Sylar does and gains his power. Hiro fights Sylar on the night, stabs him but Sylar regenerates and explodes as Hiro escapes. Ando is killed as are several million others. Five years pass and Hiro travels back in time to give a message to Peter to save Claire. Upon returning to the future, Hiro goes into timeline 3, NOT the same timeline he left from.

3. This is the timeline after "Hiros" up to "Five years gone." In this timeline however, Hiro never gets the chance to stab Sylar, if even fight him at all. This time though, Peter meets Ted (as he does in the final one) and explodes, taking New York and once again Ando with him. Claire isn't dead in this timeline. It is presumed Peter explodes slightly earlier this time as Hiro can't come to his aid as they were left in Vegas after 0.7% and never teleported to New York. After five years, the events are pretty much the same, except Sylar is no longer regenerative and Peter was the bomb. Future Hiro upon returning, replaces the Hiro native to this timeline but as the timelines are pretty much the same, the two Future Hiro's pasts are very similar. One day after returning from the subway, Future Hiro meets present Hiro and Ando and the events of Five Years Gone occur.

4. from "The Hard Part" onwards. Hiro and Ando teleport to New York before they should have arrived. This sets up a series of events which were similar to some of the events of the 2nd timeline. Hiro gets the chance to stab Sylar, this time stopping him. Peter goes to detonate later this time, giving Nathan enough time to come to a decision and save him, causing Peter to explode harmlessly in the sky.

Hope that wasn't too confusing!

Sylar has regeneration cus Suresh has a sample of clairs blood. He (Sylar) stle it from suresh and injected himself with it hence regeneration.

Clairs father was injected with clairs blood...I wonder if he will develop abilities now. Also ...the guy thats the cop ( can't remember his name) seems to be getting stronger abilities. I think the good heroes will have to all band together to stop Sylar.

Because he survived the 'fatal blow' from Hiro with help from the company - as you see in season two. It is also explained that sylar never blew up - peter did, it was assumed to be sylar by the general public, who were unaware of peter's ability.
However, if he'd met adam Monroe in the alternate future - which he didnt - he could have had the regenerative ability from him:)

Easy. After Sylar killed Peter and ate his 'brain juice', Claire found Peter and pulled the glass out of his head and Peter regenerated just like Claire had in the morgue.
Sylar had the power of regeneration because he had killed either Claire, who had that power in the first place, or Peter, who had absorbed it from Claire. Both were presumably able to regenerate after they had been killed.

I agree with Chris W but there is something he has missed out on.
Claire Bennett is alive in Five Years Gone and is summoned to the White Horse by Nathan Petrelli but we all know he turns out to be Sylar. With his telekinesis power he stops Claire in her tracks so she cant get away and takes the top of her head clean off to take her regeneration power, but that was the alternate future if the future was not changed.

????

what episode are you talking about?