Microsoft is struggling to convince consumers that Vista is strong and is the new wave for operating systems. Many people are clinging to their copies of XP, which is the longest-running and most-installed operating system by far.
The software giant recently released the first Service Pack for Vista, which has given new attention to the OS.
More than 140 million Vista licenses have now been sold, which averages out to around three copies every second since it went on sale last January.
"That's a very rapid sales rate," said Bill Gates in a news conference, reports the Wall Street Journal.