The decision today bars only private suits for damages, which in lawsuits of this kind typically means back pay.
Some of Microsoft's leading rivals, and even its biggest customers, could bring private suits, according to legal experts.
But many experts said it might be premature to assert that private suits could curb its behavior.
That followed its settlement a year earlier of a private suit, involving similar accusations, for about $10 million.
The provision allowing private suits against states for money damages was invalidated.
In fact, none of the private antitrust suits are scheduled for trial within the next year.
Yet, publicly at least, Microsoft insists that its risk from private antitrust suits is exaggerated.
Eventually, it negotiated an end to the boycott and resolution of the private suits.
Remember, this was a private suit against the President in his private capacity.
Microsoft says that the private antitrust suit, like the Government's case, is groundless.