The world's No.1 golfer said he had made some "incredibly bad decisions" but through therapy and Buddhist meditation was now "at peace" and could play the game the way he did early in his career before he became entrapped in fame and what he described as self-deceit.
Woods would not specify what he is in therapy for, calling it personal.
He also denied receiving performance-enhancing drugs for Dr. Anthony Galea, a doctor who is being investigated for distributing illegal drugs to athletes. Woods said he had received treatments for his knee from the doctor.
Woods again apologized to his mother, children and wife, Elin Nordregren. Nordegren, he said, would not be attending the tournament.
He said he realized how much damage his philandering had done to his family soon after Christmas when he entered therapy and missed his son Charlie's first birthday.
"I missed my son's first birthday and that hurts. It hurts a lot. I vowed I'd never miss another one after that. I want to be a part of my son's life going forward. It is something I regret and probably will for the rest of my life," Woods said.
And despite a five-month thrashing from the press, Woods acted like the press, with whom he has long had a chilly relationship, were his old pals. He said many of the reporters in the room he considered to be his friends, calling on them by their first names and referring to one as "bro."
Meanwhile, one of Woods' mistresses, Joselyn James, a former porn star who carried on a three-year relationship and has repeatedly called for a public apology from the golfer, was to hold her own press conference in New York.
James called the golfer a "big fat liar" and shot down Woods' public promise to better himself as "big malarky." "After the birth of his first daughter Sam, he was with me 10 days later," she said.