The core of the US government's case is that Microsoft abused its dominance of the market for operating systems by tying the software to its web browser.
Microsoft had accused the government of "gamesmanship" in the run-up to the trial, which is set to start on 8 September. The manoeuvring looked as if might delay the start of the trial.
Microsoft had been arguing that Mr Gates, the company's chairman, could only give evidence for eight hours, and had said that only eight of its officials could appear. But the judge said that he would not apply a limit to the amount of time for which Mr Gates must give evidence, and ordered 16 Microsoft officials to appear.
He also ordered the software giant to hand over the source code for Windows 95 and Windows 98. Microsoft had argued that this was its most closely guarded commercial asset.
"That source code, for a currently shipping product responsible for generating billions of dollars of revenue for Microsoft, should not be treated cavalierly," it said.