What did Ballmer know and when did he know it?

That's arguably the biggest question in the Microsoft "Vista Capable" class-action lawsuit being heard by a federal judge in a Seattle court. Documents unsealed last Thursday imply that the Microsoft CEO was in on the decision two years ago to lower technical requirements for its Vista operating system as a favor to chipmaker Intel, which pressured the software giant to slap "Vista Capable" stickers on PCs with Intel 915 chipsets, hardware that  lacked the firepower to run the full Vista feature set.

Intel allegedly stood to lose "billions" of dollars if Microsoft stuck to its original specs because the chipmaker would have been stuck with a whole bunch of the Vista-inadequate 915s. And while Microsoft's concern for Intel's quarterly earnings results was touching in that corporate bottom-line kind of way, the impact on consumers was less than heart-warming.

Stuart Johnston over at internetnews.com explains:

The plaintiffs argue that Microsoft's "Vista Capable" sticker on the boxes deliberately misled consumers to believe that new PCs that they bought prior to Vista's consumer delivery on January 30, 2007, could be upgraded to run higher-end editions of Vista that feature the Aero Glass user interface and other graphics intensive features of the operating system.

Oh, and computer maker Hewlett-Packard, which had sunk a lot of development time and money into two motherboards for Vista, wasn't loving it either. From Information Week:

"The decision you have made and communicated has taken away an investment we made consciously for competitive advantage knowing that some players would choose not to make the same level of investment as we did in supporting your program requirements," HP consumer PC executive Richard Walker wrote in an e-mail to former Microsoft co-presidents Jim Allchin and Kevin Johnson, dated Feb. 1, 2006.

"I can't be more clear than to say you not only let us down by reneging on your commitment to stand behind the WDDM [Windows Display Driver Model] requirement, you have demonstrated a complete lack of commitment to HP as a strategic partner and cost us a lot of money in the process," wrote Walker.

Indeed, the decision was hotly contested within Microsoft, with some executives arguing that it was unfair to consumers and would hurt the company's credibility. Fortunately, this is when Steve Ballmer decided to take charge and get to the bottom of the mess. Oh, wait:

Microsoft cites an e-mail in which Ballmer told then-Windows chief Jim Allchin -- who vehemently opposed the decision -- that Windows executive Will Poole was the one responsible. "I had nothing to do with this Will handled everything," Ballmer wrote, according to the Microsoft filing. "I am not even in the detail of the issues."

("I am not even in the detail of the issues"? Channeling Sarah Palin!)

Of course, that response was in the heat of the moment. Since then, Ballmer has assumed full responsibility for the situation. Oh, wait again:

"The e-mails highlighted by the plaintiffs reflect the normal back-and-forth discussion about an internal decision Microsoft made in January 2006, long before it began communicating about the Windows Vista Capable program to consumers in May 2006," said a statement by David Bowermaster, a Microsoft spokesman, e-mailed to InternetNews.com.

"Microsoft CEO Steve Ballmer has no unique knowledge of the facts in this case," Bowermaster continued. "Anything he knows about the Windows Vista Capable program he learned from executives whom he empowered to run the program and make decisions."

Shortly after a January 2006 phone conversation between Intel CEO Paul Otellini and Ballmer, Otellini sent "a note to Steve thanking him for listening and making these changes." Yet Microsoft attorneys characterized that phone discussion as a mere "courtesy call."

Consequently, internetnews.com reports, Microsoft attorneys claim "there is no reason for Ballmer to take a day out of his busy schedule to provide a day-long deposition in the federal class action suit."

It seems to me that Ballmer could clear up a whole lot of confusion surrounding this entire matter if he would voluntarily submit to questions under deposition, something Redmond's army of lawyers has asked the judge in the case to block.

But hey, what do I know? After all, last year I bought an HP laptop powered by Vista.