Microsoft didn't lose any lawsuit in the US for for tying its web browser to Windows; the prosecution realized how shaky the argumentation for that'd been and subsequently dropped that claim.
From your own link: "At the appellate level, the U.S. government dropped the claim of tying given that—as laid out in Section 1 of the Sherman Act—it would have had to prove that more harm than good resulted from the instance of tying carried out by Microsoft.".
Non-rhetorical question: did the change in the ruling party in the US (in early 2001) come between the original case and the dropping of the claim?
I'm wondering whether the cause was more "a new head of the relevant department had a different attitude towards antitrust enforcement" (or possibly even "a different attitude towards Microsoft") than "the prosecution realized how shaky the argumentation had been".
It seems a fairly accurate summary. DoJ was unlikely to win the appeal, so they settled.
As a side not, that Wikipedia article is far from neutral:
> … Microsoft responded that the company would offer manufacturers a choice: one version of Windows that was obsolete, or another that did not work properly.
The GP claimed "Microsoft didn't lose any lawsuit in the US for for tying its web browser to Windows". This is absolutely false. From the Wikipedia link,
> Judge Thomas Penfield Jackson issued his findings of fact on November 5, 1999, which stated that Microsoft's dominance of the x86-based personal computer operating systems market constituted a monopoly, and that Microsoft had taken actions to crush threats to that monopoly, including Apple, Java, Netscape, Lotus Software, RealNetworks, Linux, and others.[5] Judgment was split in two parts. On April 3, 2000, he issued his conclusions of law, according to which Microsoft had committed monopolization, attempted monopolization, and tying in violation of Sections 1 and 2 of the Sherman Antitrust Act.[17] Microsoft immediately appealed the decision.[18]
The government may have agreed to a settlement on appeal but Microsoft lost the initial suit.
If you want to be pedantic, yes, the district court did indeed rule against Microsoft with regards to the tying claim.
However, when most people discuss the result of a lawsuit you can generally infer they are referring to the ultimate decision after all appeals are exhausted (as opposed to any particular intermediate decision which could get reversed and then reversed again).
Since the appeals court overturned that particular claim, one could reasonably argue that the district judge ruled incorrectly, and in the eyes of the legal system Microsoft, did not, actually lose.
(Note that I am speaking here only in regards to the tying claim, as the appeals court did affirm that Microsoft lost on several of the other claims related to Windows licensing for OEMs.)