But the wider competitive landscape has changed greatly since the Commission started its action against Microsoft. Software applications on mobile phones usually bypass browsers entirely. Tech companies are now often less concerned with Internet browsers and more concerned about Google Inc.'s dominance in Internet search technology, Facebook's dominance in social networking, and Apple's dominance on mobile devices.
"For technology companies, often the best policeman is technological progress itself," Sabino said.
Rather than imposing unilateral fines, Almunia has advocated negotiated settlements since he took over as commissioner in 2010. He believes that competition issues are best resolved quickly and that slapping big fines on companies years after the fact does little to help consumers.
But he said the whole point of a settlement is undermined when companies then don't abide by its terms.
"They must do what they committed to do, or face the consequences," he said.
Almunia conceded that the Commission had been "naive" in appointing Microsoft itself to oversee compliance with the agreement, and said the Commission won't allow that in the future.