When Edward died there was 3 people that wanted to be king, Harold Goodwinson, Harold Hardrada and William of Normandy.
I have the 20 year experience
Harold Godwinson, Earl of Wessex was proclaimed king by the Witan.
William of Normandy was a relative of king Edward. William claimed that Harold of Wessex promised him the throne. He said he could repeat the job of being king of England.
Harold Hardrada was a previous king for 20 years so they knew he had the skill and ability to be king again. He was in charge of the army and he didn't lose many wars therefore he was a reliable king.