An abusive monopoly? Microsoft never had a monopoly, much less an abusive monopoly. If they had, there's a very long list of products and companies that did survive Microsoft that would not have.
They had market power, not a government granted right to a market (aka a monopoly). There's no historical evidence to suggest Microsoft was unbeatable. Rather, there's a lot of evidence to suggest very few companies tried to compete with Windows once it achieved scale. Neither Sun nor Oracle ever launched a full fledged Windows competitor in the consumer space, neither did AOL or Netscape. And Apple lost due to its own mistakes, more than admitted by Jobs after the fact; ditto IBM.
And if you want to talk market power. Microsoft beat Apple, who was ten times its size. And they beat IBM, which was 100+ times its size. How? The same way Android has beaten iOS in smart phones when it comes to market share: distribution across the widest selection of hardware vendors.
Re inflating prices. Actually Microsoft lowered prices substantially.
You should look up how much productivity software cost before Microsoft created Office, and how much easier it was to buy and sell their software. They undercut everybody at the time. Microsoft also was instrumental in vastly bringing down the cost of personal computing by leveraging a standard across consistent hardware. They also made it extremely easy to distribute software, courtesy of a standard, bringing down the cost for software by providing economies of scale. Meanwhile, competing platforms were far more expensive (including Apple's solutions). Also, Microsoft has always charged half or less for Windows than what Intel does for its good consumer processors.
The DOJ got involved because competitors who either screwed up and failed to compete (eg Netscape), or were simply scared (Sun), complained.
Wired's The Truth The Whole Truth article about the case more than spells out how much of a witch hunt it was.
The DOJ tries to control any wildly successful company with market power. For the government, it's all about power over the economy and bringing companies to heel. Anti-trust has little to do with monopolies (if it did, Verizon and AT&T would be broken up).