Microsoft says that in the first 100 days that Vista has been available they've sold almost 40 million copies:
Gates said an accelerating consumer shift to digital lifestyles had helped make the operating system the fastest-selling in history, and that premium editions have accounted for 78 percent of Vista sales.
"I'm really thrilled at how this has come together," said Gates during a speech at Microsoft's Windows Hardware Engineering Conference 2007 in Los Angeles.
Windows operating systems run on more than 95 percent of the world's computers and represent the Redmond, Washington-based company's biggest profit driver.
Vista, which Microsoft introduced on Jan. 30, also marks the first major operating system upgrade in more than five years from the world's biggest software maker.
Gates said Windows Vista allows many niche-oriented PC functions to move into the mainstream, from Web cameras to various home remote-controlled items.
Gates also said that the company named its next-generation Windows Server software -- formerly known as "Longhorn" -- Windows Server 2008.