Microsoft Corp.’s next version of the Windows operating system is almost ready for prime time.

That’s one message Chief Executive Steve Ballmer delivered on the eve of the official opening of the International Consumer Electronics Show.

The world’s largest software maker also disclosed deals to make its Live Search programs the default search engines on more personal computers and mobile phones. And it announced a new version of its Ford Sync in-car technology that folds in the voice-operated directory service TellMe, which Microsoft bought in 2007.

For years, the opening keynote at CES belonged to Microsoft Chairman Bill Gates, whose status as industry pioneer justified the sweeping visions of the future he’d build into his speech. Gates passed the mantle on when he stepped down from day-to-day operations at Microsoft last summer, and Wednesday marked Ballmer’s first time making the high-profile address.

“It feels like we’ve entered a period of reduced expectations, a time when we may be tempted to temper our optimism and scale back our ambitions,” Ballmer said, in a nod to the recession. “But no matter what happens with the economy or how long this recession lasts, I believe our digital lives will only continue to get richer.”

Ballmer said Microsoft would continue to invest more in research and development than its technology peers.

The CEO announced that a nearly final “beta” test version of Windows 7 will be available Friday for regular PC users to download and tinker with.