Total number of Windows 7 users surpass Vista
During July 2010, the market share for Windows 7 surpassed that of Vista. While XP is still more established, it's install base has declined some. Windows 7 is more functional and secure, especially for new 64 bit systems which are the future for computing.
Windows 7 Passes Vista in Users, XP Still King
QUOTE: Windows 7’s market share for July reached 14.46 percent, according to the firm, compared to 14.34 percent for Windows Vista. That represents a significant change from October 2009, when Windows 7 was released into a market where Vista ran on 18.83 percent of personal computers. Net Applications noted, however, that “Windows XP is still the leading operating system by far, with double share of Vista and 7 combined.” The firm estimated Windows XP’s market share at 61.87 percent.