Microsoft has sold 210 Million Copies of Windows XP.
From Reuters: “Microsoft Corp. said on Monday that retail and new PC sales of Windows XP, its flagship operating system, have grown to more than 210 million copies since the product was launched two and a half years ago. …
“Windows lead product manager Greg Sullivan. … claimed that the actual number of computers using Windows XP was much higher, since it doesn’t include software loaded onto machines under corporate licensing agreements, which typically are not closely tracked since they are sold under volume licensing agreements.”
Ed Bott 