Microsoft Corp. sold 20 million consumer copies of its new Windows Vista operating system worldwide in February, but at least one expert in the industry say the number is nothing tobrag about.

Microsoft announced the sales figures Monday, in a statement touting Vista's "high global sales." By comparison, Windows XP, Vista's predecessor, sold 17 million copies in the two months following its October 2001 launch. Vista's brisk sales have made it the fastest-adopted operating system in history, Microsoft said.

"It's a stronger than expected start," admitted Bill Mannion, a director of product marketing for Windows.

But when viewing the growth of the worldwide computer market, that number isn't as high as it could be.

"[The sales figure] probably should be more," said Michael Silver, vice-president of research at the Gartner technology research group.

In 2002, consumers bought 51 million PCs worldwide. Analysts predict as many as 96 million will sell in 2007.

'Numbers aren't all that great'

Starting in October 2006, many PC manufacturers offered coupons for free or low-cost Vista upgrades for use once the software became available at the end of January. Microsoft's February sales total includes those upgrades as well as licences ordered by PC makers to install the software on new computers, copies sold in stores and downloads from the Windows Marketplace web store.

Silver estimates PC makers sold 12-15 million PCs with Windows XP Home Edition over the holidays. Depending on how many of those included Vista upgrade coupons, that could account for a significant amount of the 20 million Vista copies sold.

Although Microsoft wouldn't say how many Vista upgrades were ordered in that time frame, Dell Inc. spokesman Bob Kaufman said about two-thirds of its holiday buyers registered for the upgrade.

"That would say that those [Vista sales] numbers aren't all that great if that includes all that backlog," said Silver.

Despite Vista's apparent out-selling of XP, February statistics show shipments of Vista to U.S. retailers trailed XP's first-month shipments by about 56 per cent, according to the NPD Group, which tracks retail software sales.

Microsoft wouldn't reveal the number of Vista copies sold at retail, though it has said in the past that 80 per cent of Windows revenue comes from sales to PC makers.

The retail channel may not be the most important for Microsoft, but NPD analyst Chris Swenson said the decline indicates some consumer reluctance to embrace the new operating system.

"That's kind of a big deal," Swenson said. "Our thesis was, every review of Vista talks about how strenuous the hardware requirements of Vista were. I think customers got the message."

Swenson also blames Microsoft's advertising strategy, which had little TV penetration, for the drop in sales.

"Microsoft should have more TV ads selling Vista than Apple has criticizing Vista," he said, referring to a series of Apple Inc. commercials that lampoon Vista upgrades as difficult and dangerous procedures.

Shares of Microsoft rose 20 cents after the announcement to close at $28.22 US on the Nasdaq stock market.

With files from the Associated Press