Every guard try to kill me :S What can I do?

You will have a death warrant on you - you have done something real bad!!

On XBox there is no way out except to reload a save game
On PC there are console codes to get round it.

EDIT:- Welcome to these forums

the code on the pc is:

setpccrimelevel 0

well did you clear your bounty, because if you didnt thats probably why, if you did the exact thing happened to me, i got a 50 thousand bounty i paid it and all the guards tried to kill me. They just probably think the world would be a better place without your character

This has also happen to me, thanks for the cheat

I got wantet when I took the Vampire Ring, Thx!

Well, as Rough said...if you have a death warranton you, the only thing to do is to use the console, if not the warrant will never go away....but Imust say, you nearly...NEARLy deserve the guards running about trying to kill you....it's yourselves who have done things that gotten you into this.......it really is your own fault.

But still, It's not funny trying to be killed all the time, so I pity you as well...but take my advice...stay out of these evil affairs, and dont do such things that give you bounties...and if you do, go to the thieves guild and pay the bounty straight away. Thats my advice.

As the people above answered you have to clear your bounty......Still,don't cheat!Pay your tribute,or pay the guy in thievs guild to settle things for you......

I must ask another question:
Guards in Vivec
I ''borrowed'' one of their helmets and they were chasing me every time i was in Vivec! No bounty,they were just pissed! I never figured how make this stop....Still it doesn't metter anymore,now it's time to play Oblivion!

Aye, they felt insulted for you wearing their armour. I don't know what can be done against it. (Apart from using the console and avoiding them for eternity)
One thing you could do to prevent it (pc only) is to go to the construction set and remove the script attached to the helmet and the cuirrass. I believe that that is what makes the Ordinators so aggressive. But if you believe that that is cheating, you could always make your own armour that looks exactly the same (just give it a new id name and then remove the script on the new object). You could then have it been given as the reward of a quest or something.

You can try going to a Thief's Guild. Some guys there can remove your punishment (you'll have to pay for it though!).