Updates to this story
McLeish said that Redmond had had enough of XP, Office 2003 and IE6 and was taking steps to kill them off.
She said that it was not in Microsoft's interest to support XP: "It has a vision of moving people ahead on operating systems. That's the business intent."
Microsoft said that it will not craft a version of IE9 for XP because it's adding graphics processor-based acceleration to the browser.
That acceleration relies on APIs that are built into Windows 7 and were added to Vista in October 2009, but that are not available in the older OS.
XP is slated for final retirement in April 2014, nearly 13 years after its release.
Both Google and Mozilla are working on boosting their Chrome and Firefox browsers by tapping into hardware acceleration, even on XP, says this report.