SAN JOSE, Calif. (MCT) — Windows Vista may have driven Sandra Lew straight into Apple’s arms.

There’s a chance Windows 7 could win her back.

“My last laptop had Vista, and it was a terrible experience,” said Lew, a 28-year-old marketing specialist who was shopping for a new computer in San Jose last week.

Though recently unemployed, and watching her wallet, Lew said her frustration with Microsoft’s widely criticized Vista operating system was making her lean toward a more expensive MacBook that runs Apple’s software instead. But she had heard good things about Microsoft’s new Windows 7, and she planned to do more research before making a final choice.

Microsoft is counting on its new operating system to mend relations with customers like Lew and to shore up what is a core business for the world’s largest software company. And the $244 billion-a-year PC industry is fervently hoping the new software will help bring buyers back into stores, after a steep drop in sales earlier this year.

Windows 7 has received favorable reviews thus far. But rather than create an immediate sales bonanza, experts caution that it is more likely to have an impact over the long term.

Microsoft still dominates the PC operating system, with Windows Vista or its predecessor Windows XP running on 88 percent of PCs in the United States and 90 percent worldwide, according to the Gartner research firm.

But even if that’s unlikely to change in the near term, there are signs that Windows’ ubiquity is waning a bit.

Since its release two years ago as the intended successor to XP, Vista has been widely panned as bloated and slow. In the United States, Apple has increased its market share for computers running the Mac operating system. And some PC makers have even toyed with the idea of using Linux or Google’s Android for low-powered netbooks.

Meanwhile, PC makers have been clobbered by a recession that slowed new computer sales early in 2009, for the first time in years. Some analysts have suggested that Windows 7 could be a powerful force, along with the recovering economy and upcoming holiday sales, for stimulating new purchases in the second half of 2009.

“The launch of Windows 7 will be a major positive for the PC industry,” predicted analyst Matthew Wilkins at iSuppli, an industry research firm.

Retailers like Best Buy are planning promotions around the new release.

In addition, Hewlett-Packard and other PC makers have been introducing new models, including a host of lightweight portables at lower prices and computers designed to take advantage of touch-screen capabilities in the new operating system. Most will come with Windows 7 preinstalled.

Still, several analysts said they don’t expect a sudden surge of consumers who feel driven to buy the new operating system — or to buy new computers on the basis of Windows 7 alone.

“Consumers buy a new PC if they need one. They don’t buy PCs because a new operating system is available. And they don’t spend $100 or more just to upgrade” by installing a new operating system on their old computers, said Mikako Kitagawa, who follows the PC industry for Gartner.

Replacing XP with Windows 7 on an older computer is not a simple process, she noted. “Unless those consumers are pretty tech-savvy, or geeky, they don’t want to do anything complex. They want to do things as easy as possible.” In recent months, market researchers say that PC sales have already begun to pick up, along with the overall economy. So while some predict a flurry of consumer activity this fall, several experts and industry executives have said they expect the bigger surge will come when business budgets are replenished in 2010 — and corporate buyers start replacing aging fleets of laptops running on 8-year-old Windows XP.

More than two-thirds of PCs in the United States are still running XP.

But analysts say the older operating system is more of a concern for big businesses.

Consumers who bought new computers in the past year generally received Vista preinstalled by default. But many corporate IT departments, under pressure to cut costs during the recession, have postponed buying new PCs for their employees. They also avoided upgrading to Windows Vista, preferring to stick with the more proven and reliable XP.

Increasingly, however, new business software applications may be incompatible with XP. And maintaining hundreds of old computers can be a major cost.

For corporate users, “machines that are 4 or 5 years old are costing more to keep than to buy a new machine,” Intel CEO Paul Otellini recently told analysts. Intel supplies the processors for most PCs, so it monitors sales trends closely.

As businesses embark on a new budget year, they’ll begin buying large numbers of PCs in 2010, said HP executive Todd Bradley, during a recent conference. Bradley, who runs HP’s PC division, said Windows 7 should help with those sales.

Unlike businesses, however, many consumers did not hold off on buying new PCs during the recession — although many opted for lower-cost models.

“A lot of people now view their PC as a necessity,” said Justin Barber, a spokesman for the retailer Best Buy. He said that means consumers who decide to buy a new computer aren’t likely to wait for the release of a new operating system.

Many PCs sold since June have come with coupons for a free upgrade to Windows 7 when it’s available. So there was little reason for consumers to wait for the formal release date, Barber said, suggesting there won’t be an explosion of pent-up demand this week.

Still, iSuppli’s Wilkins said in a recent report that Microsoft’s efforts to promote Windows 7 “will get more people thinking about PCs.

This can only be a plus for the market.”