To understand the microsoft case you need to understand the ATT breakup. The Bell System (ATT) was granted an illegal monopoly, by the US government, in secret, that lasted about 100 years. The government desperately wanted telephones in everyone's house using a common system and Bell put the screws to them, demanding a monopoly similar to what the government had given the railroad industries.
Fast forward to the ATT breakup. After 100 years, the rest of the world were making products and innovating (answering machines, faxes, etc.)--products for public consumption. As far as telephony goes, America was starting to look pretty stale and primitive. ATT had a government supported lock on every phone line, and only their overpriced products could be legally attached to that line. Creating or attaching unauthorized devices to an ATT line was a crime and many people were punished.
Finally ATT was broken up and things like cubby hole paper messaging were replaced by modern systems, etc...the world changed.
In the MS case they basically have the same issues. They have secret APIs that no one else can use, public APIs that crash or are unstable if you use them, mountains of internal memos on how they break other companies' software to favor their own. It's illegal to clone windows--patents, copyright, etc, as we see enforced everyday. Many people believe MS was handed a similar "100 year" secret monopoly by the government just as they did for ATT--the goal being a common OS in everyone's house.
Now fast forward to the trial. It was a slam-dunk--all kinds of memos, emails, perjury showing MS committed multiple crimes. In fact, a smaller company in Florida, a grocery chain committed similar crimes, was chained shut and had their business licenses voided around the same time. No business license no sale--but I digress.
The penalty for MS was a breakup of the company. However, the Judge, Thomas Jackson, with decades of legal experience, conveniently provided evidence of bias within weeks of the trial's end, and the penalty was thrown out.
The incoming Bush Administration put a "paper tiger" Federal Judge (Kathleen Kotar-Kelly) in charge of overseeing what feeble penalties remained, and she has consistently let MS continue with their old behaviors.
Corporate criminals rarely get jail time, unless the government wants to parade them in front of the cameras for PR purposes. The wealthy can afford the best lawyers and withstand the massive cost of extended trials. And it does usually pay off in lower penalties and fines. In terms of crime, usually only those convicted of physically harming people go to prison, others usually pay hefty fines. MS has certainly been convicted in Europe and paid substantial fines.