The American, a winner of 13 grand slam singles titles, suffered a sprained ankle last week and admits her preparation has been far from ideal coming into the opening major of 2012 in Melbourne.
But she vowed she will continue to fight through the pain to avoid the disappointment of defeat.
Asked whether she still gets a buzz from playing top-level tennis, she said: "Yeah, I get the same buzz, if not more. I love playing majors and I love competing.
"More than anything, I hate losing. That makes me really hungry to work harder to get the results that I want."
And the hatred of losing is still as fierce now as when she started out in 1998.
"Yes definitely. It's funny because it can go down because you get used to tough matches and you learn how to lose better," she said.
"I definitely think I have, but it's still really hard for me. So that just feeds my hunger to work harder."
As for the injury, the 30-year-old, who faces Austrian Tamira Paszek in the first round, admits it is still giving cause for concern.
"I really tested my moving today for the first time so I feel a lot better with it," Williams said.
"I'll kind of know more tonight, because today is the first day I really, really, really pushed it. I've been taking it easy for a long time now. But overall I feel really good."
Williams missed the 2011 Australian Open after suffering a serious foot injury and her comeback was delayed further by the discovery of a blood clot on her lung.
On her last two appearances in Melbourne, she has taken home the title and she was delighted to renew her love affair with Australia.
"I absolutely love it here. I love the people here, I love the atmosphere," she added.
"More than anything, when I stepped out on Rod Laver Arena for the first time, I just love that court. I love the way it feels and the way I move on it and the way I hit on that court. It's an indescribable feeling.
"I was really excited. It kind of pumped me up more just to say I'm definitely going to get through this injury."
Williams is just one of the leading ladies to suffer an injury scare in the build-up to the event with world number one Caroline Wozniacki and defending champion Kim Clijsters also seeing their preparation disrupted.
Speaking today, however, both declared themselves fit and raring to go.
Wozniacki was reduced to tears after injuring her left wrist during her quarter-final defeat to Agnieszka Radwanska at the Sydney International last week, but she said: "It's okay, it's getting better. I'll be ready to play on Monday. I'm looking forward to it. It's exciting to start the first grand slam of the year. It will be 100%.
"Playing in Sydney, when it happened, I really felt the sharp pain, I was a bit concerned. But now it feels good, so I'm okay."
Clijsters was equally bullish despite having to withdraw midway through her semi-final against Daniela Hantuchova at the Brisbane International last week.
"I'm doing good," she said.
"I think what happened in Brisbane was something that I knew would only need a few days to get better and it did."
Williams' return to competitive action has only increased the competition in the women's game.
Four different women - Clijsters, Li Na, Petra Kvitova and Samantha Stosur - claimed last year's grand slam crowns and Clijsters suggests this year's Australian Open is wide open.
She said: "Of the four girls who won last year, besides Serena, who is probably more powerful than us, it's very close.
"So I think on any given day, whoever plays that little bit better can win."