NEW YORK -- Aiming to "wow" millions of computer users, Microsoft Corp. launched its Vista operating system for consumers yesterday with a series of flashy Manhattan events and midnight sales at stores around the world.
Two months after arriving for business customers, the first major Windows upgrade in more than five years promises consumers a slicker 3-D look, improved security and search tools, and a host of multimedia and entertainment features.
While promoted by Microsoft executives as an enormous step forward, many reviewers have been more reserved, calling Vista better than the current XP system and full of subtle improvements, but not a revolutionary advance.
Many industry experts, noting Vista's heavy demands for processing power and memory, also have warned consumers to hold off on upgrading and wait to buy a PC with Vista installed. Depending on the version and whether consumers choose to upgrade XP, Vista sells for $100 to $400.
"Windows Vista is key to the era we have today," said Microsoft Chairman Bill Gates, describing what he called this decade's vision of the "digital lifestyle. ... This is the most tested and highest-quality release we've ever made," he said.
One Microsoft launch slogan is "the 'Wow' starts now," which refers to the notion that computer users say "Wow" when they first see Vista.
Gates spoke at a launch party in a Times Square theater decorated as a dance club complete with pounding music, a disc jockey and roaming spotlights projecting "Windows Vista" and "Microsoft Office" across the floor.
Gates, who walked onstage after being announced like a rock star, was later joined by top executives from PC hardware firms, including Dell, AMD and Intel.
Microsoft took Manhattan in other ways, with acrobats in company colors hanging from the side of a building unfurling flags to create the red, green, blue and yellow Windows logo.
Microsoft also was launching new versions of its Office business suite, including the programs Word, PowerPoint and Excel, and its Exchange e-mail software.
Vista is almost certain to have a wide reach, since more than 90 percent of computers run a Windows operating system, and most new PCs will ship with Vista installed.
At an earlier launch event at a posh and cavernous Manhattan restaurant, Dell Inc. Chief Executive Officer Kevin B. Rollins said that since his company began taking orders for PCs with Vista over the weekend, Dell's Web site traffic jumped 20 percent and tens of thousands of the computers have been sold.
However, the domination of Microsoft's software has been threatened in recent years because of the spread of similar Web-based and open-source programs, some of them free.
Shares of Microsoft fell 7 cents on the Nasdaq stock market yesterday to close at $30.53.
Vista's debut marched across the globe yesterday, beginning in such places as New Zealand and Tokyo, where people waited outside stores for midnight openings.
Besides a release spanning 70 countries, Microsoft also was offering the operating system as an Internet download for the first time.
While there were midnight sales planned in the United States, customers have not been camped out for days waiting for Vista. Such scenes were common late last year for the debuts of the latest video game consoles.
The Vista launch lacks that degree of excitement, in part, because with Vista, there's "really nothing new you could not do before" with XP, such as chatting online, sending e-mail, watching movies or listening to music, said Roger L. Kay, president of Endpoint Technologies Associates, a research firm.
Kay said the biggest changes are not obvious.
Those improvements, he said, include a prettier interface, more intuitive controls, a powerful search tool for finding files and programs, and much better security.