Earlier in the morning, US District Judge Colleen Kollar-Kotelly said she would allow the states' attorneys to use portions of depositions from 13 additional witnesses, even though the states' lawyers submitted these additional witness names after the deadline had passed.
Nine states and the District of Columbia refused to join the US Department of Justice and nine other states in a settlement with Microsoft last November. The holdout states are seeking stricter remedies to the software company's anticompetitive behaviour.
Resuming his questioning of Andrew Appel, a professor of computer science at Princeton University, Microsoft attorney Steven Holley asked the witness about his support of the states' proposed remedies that were outlined in Appel's written direct testimony.
Holley asked whether Windows would be at a competitive disadvantage versus other PC operating systems, such as the Mac OS, if Microsoft was required to remove the code of its Internet Explorer browser from the Windows operating system as the states suggest, which would also remove the HTTP (Hypertext Transfer Protocol) protocol for searching the Web from the OS.
Appel answered that PC vendors that sell what the states' remedies refer to as an "unbound" version of Windows - a stripped-down edition that does not include extra software such as a browser - would be likely to replace Microsoft's Web browsing software with a competitor's product, and that the operating system would not, therefore, be at a competitive disadvantage.
"Presumably the [PC vendors] will do what they think will sell computers," the professor said. Appel conceded, however, that the states' remedies would not require PC makers to make such a substitution.
The Microsoft attorney then asked if software developers would find Windows less attractive if it did not include a Web browsing function.
Appel answered that he did not think so, adding that developers could also choose to use a non-Microsoft version of the HTTP protocol. But that would force developers to distribute the protocol to all customers of their software, Holley countered.
"Yes, I think that would be easy to do," Appel responded.
The attorney then engaged the witness in a lengthy debate over which portions of Windows Microsoft would need to remove in order to satisfy the states' definition of unbound Windows, attempting to make the point that the states' remedy is confusing.
Microsoft could keep some fragments of its middleware - software such as its Web browser and media player that are integrated with the OS - in the unbound version of Windows if those fragments were called upon by the operating system to function, as long as those middleware fragments were hidden from third-party software developers, Appel said.
At one point, Appel said he did not know if Holley's characterisation of what components could be kept in the unbound version of Windows versus those that must be removed was appropriate.
"If you don't know what's appropriate, how's Microsoft supposed to figure it out?" Holley asked.
Earlier in the morning, Kollar-Kotelly decided that she would allow the states to use portions of the depositions of 13 additional witnesses, including the video deposition of Microsoft chairman Bill Gates. Last Saturday, the states notified both Microsoft and the judge of their intentions to include the depositions of 18 Microsoft employees in its case.
The witness lists for the remedy trial were finalised in early February, Kollar-Kotelly reminded the states, yet Saturday was the first she had heard of the additional 18 names. The judge had set guidelines for the remedy hearing - such as keeping each side to only 20 witnesses and 100 hours of court time - in order to limit its scope and length.
Kollar-Kotelly accused the states of trying to "end run around the time allocation" by submitting 18 additional names after the deadline. The states' attorneys responded that they misunderstood the judge's schedule for naming witnesses, and added that they would whittle the list of 18 additional witnesses down to those who were also on Microsoft's witness list, which resulted in 13 names.
Despite claims of prejudice by Microsoft's counsel, Kollar-Kotelly agreed to let the states use portions of the 13 Microsoft employees' depositions in their cross examinations.
During this hearing, which began on 18 March, Microsoft and the litigating states have been presenting arguments in favour of their proposed remedies to the anticompetitive behaviour that a US court of appeals last year ruled Microsoft engaged in.
Kollar-Kotelly will make the final decision on which remedies are imposed.