With less than a month to go before Windows 7 is formally launched to the public, Microsoft's CEO said in a letter to customers and developers that the software tops all of the company's previous efforts in the OS market.

Windows 7 screen shot
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"Windows 7 is the best PC operating system we have ever built," said Steve Ballmer, in a note that was released early Tuesday by Microsoft.

Ballmer touted Windows 7's security, management, and energy efficiency features, and described it as an OS that is right for an era that is defined by what he called "the new normal."

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"I believe the new normal requires a kind of efficiency built on technology innovations that enable businesses and organizations to simultaneously drive cost savings, improve productivity, and speed innovation," wrote Ballmer, in his latest executive e-mail.

Ballmer said Windows 7's streamlined interface, which ditches many of the intrusive security measures employed by Vista, will increase worker productivity, allowing, for instance, companies to increase billable hours for mobile workers to the tune of $600 per PC.

"This could return the equivalent of one-half of one percent of the company's current gross annual revenue to the bottom line," said Ballmer.

He also claimed that Windows 7's enhanced management and energy saving tools can save municipalities like the City of Miami as much as $400,000 annually in IT overhead costs. "Businesses aren't alone in their struggle to respond to the new normal. Governments must figure out how to deliver more services on budgets that are sharply constrained by falling revenue," said Ballmer.

Microsoft desperately needs Windows 7 to be a hit with consumers and businesses. Vista was widely panned for its sluggishness, steep hardware requirements, and lack of compatibility with older software. Partly as a result, Windows sales have slumped badly in recent quarters.

Windows 7 goes on sale to consumers Oct. 22nd and is already available to Microsoft business customers. Surveys indicate the vast majority of corporations will wait at least a year before deploying the software.