Users have known it all along but a Microsoft executive has finally admitted that Vista was not all that it could have been.

In what has been the clearest condemnation yet of the company's most recent operating system, Charles Songhurst, Microsoft's general manager of corporate strategy, said that the product hadn't really delivered for Microsoft.

"What people underestimate is the importance of good or bad products, And sometimes your products are good, sometimes the products are bad. And I think Vista was a less good product for Microsoft," he said.

Windows 7, on the other hand, is much better than good, Songhurst argued. "Windows 7 is an extremely good product from Microsoft. It's been brilliantly developed, and I think people probably underestimate the effects of the bad products and the good products."

In the past, Microsoft's top managers have limited their public criticism of Vista to oblique comparisons with the new Windows 7. Last October, for example, CEO Steve Ballmer called Windows 7 "Windows Vista, a lot better."

A month later, others, including Stephen Sinofsky, who heads Windows development, acknowledged mistakes had made with Vista, but swore that they would not be repeated with Windows 7.

Company executives' private opinions of Vista were much more revealing, however. According to internal Microsoft emails disclosed in 2008 during a class-action lawsuit, senior executives and a board member griped about Vista shortly after it was released in early 2007, saying it was missing drivers and crippled their new PCs.

For the most part, Windows 7's reception by analysts, users and reviewers has been positive: "If you're a Vista user, you'll do well to upgrade to Windows 7; it's a superior operating system," said Computerworld's Preston Gralla of the final code .

Songhurst also dismissed the idea that Apple and Google, with their Mac OS and Chrome OS , respectively, pose a threat to Microsoft's dominance in the operating system market.

"Apple has two very big structure advantages over us," Songhurst acknowledged. "The first is its vertical integration ... there's always the quality of experience you can do if you go vertical that you can never do as a horizontal player."

The downside to that strategy was that it limited Apple's ability to make moves on the enterprise OS business, where Microsoft dominates the desktop even more than in the home. "It's particularly constraining in the enterprise when you don't provide the level of custom-ability, and extensibility," Songhurst said. "It's very difficult to see how Apple becomes compelling for the CIO over the next decade, and if they don't become compelling to the CIO, they're not going to make the inroads into the enterprise."

Apple, however, has manoeuvered to make its operating system, and thus its computers, more attractive to CIOs. Late last month, Apple launched Mac OS X 10.6, aka Snow Leopard , which includes built-in support for Microsoft Exchange Server 2007 .

As for Google's Chrome, Songhurst was just as optimistic that Microsoft would be able to fend off that rival. "Because [Chrome OS] doesn't exist yet, it's hard to say much about it," Songhurst started. "If it comes out and it's the world's most amazing operating system, and does things that no one has ever thought of, it's a real problem for Microsoft. [But] if it's a similar version to a Microsoft operating system, but at a lower price point, or funded by search, it's much less of a threat.

"The quality of Windows 7 is the best defense we have in this space," Songhurst said.

Some analysts have agreed . In an interview shortly after Google announced Chrome OS in July, Michael Cherry, an analyst with Directions on Microsoft, was confident that Google could face the same challenges as Microsoft in the long run. "We didn't get to where we are with Windows because Microsoft set out to build a slow, massive operating system. They kept adding functionality," Cherry said at the time.

"What Google will face is application developers who say, 'Here's what we'd like to do,' and Google will realize that their OS doesn't support that. And then they'll expose an API or add functionality. And lo and behold, it's a little bigger," he said.

Google has shared little about Chrome, saying only that it will launch in the second half of 2010 .

Not surprisingly, Microsoft's Songhurst was upbeat about Windows', and Microsoft's, future.

"What you hear at the moment is a lot of commentary about how [the OS business] is commoditized, how it's hard to get more innovation in it," he said during the Q&A portion of the conference. "And I think what you'll find is a renewed belief in innovation, and a renewed belief in the Windows franchise.

"When Windows is executing well, Microsoft is in good shape," said Songhurst.