SAN FRANCISCO - Microsoft is escalating its efforts to bring the latest version of Internet Explorer to more than 700 million personal computers in an attempt to re-establish the software maker's browser as the best way to surf the Web.  

Tuesday's release of Internet Explorer 10 is aimed at PCs running on Windows 7, the most used version of Microsoft Corp.'s flagship operating system for PCs.

A preview version of Internet Explorer 10 has been available for Windows 7 machines since mid-November. The final version of Internet Explorer 10 will be automatically sent to all Windows 7 computers set up to get updates.

Internet Explorer 10 is primarily designed for tablet computers and other devices responsive to touch, including a new breed of PCs.

Even though relatively few Windows 7 PCs can be controlled with fingers on a display screen, Microsoft is confident Internet Explorer 10 will still have widespread appeal because it loads websites 20 percent faster than its predecessor, said Ryan Gavin, Microsoft's general manager for the browser.

''Tens of millions'' of people downloaded the preview mode on Windows 7, Gavin said.

About 90 percent of Windows PCs have been programmed to get the automatic updates, Gavin said. It could take several weeks before the Internet Explorer 10 updates are sent to all those computers. Internet 10 doesn't work on XP, Vista or other older versions of Windows.

Internet Explorer 10 already comes with machines running Windows 8, a dramatic makeover of the operating system that came out four months ago. More than 670 million PCs rely on Windows 7.

In addition, more than 60 million PCs and other devices have licensed Windows 8.

Microsoft, which is based in Redmond, Washington, is counting on Internet Explorer 10 to reverse recent trends in the Web browser market. By some estimates, Google Inc.'s Chrome browser has supplanted Internet Explorer as the world's most popular browser.

Other research firms still assert that Internet Explorer remains the most widely used, although all measures show it has been losing market share to Chrome, Mozilla's Firefox and Apple Inc.'s Safari.

The new Web browser is the latest in a procession of products that Microsoft has unveiled in the past four months.

Besides Windows 8, Microsoft has released a tablet computer called Surface, an update to its Office suite of programs and an overhaul of its Web mail service, which is now called Outlook.com.

Microsoft believes the barrage of new products will prove it remains on the cutting edge of the latest technology trends, 38 years after the company's founding.

The push hasn't swayed Microsoft's stock, which is hovering around the same price as when Windows 8 came out in late October.

Microsoft's stock gained 18 cents to $27.55 in morning trading Tuesday.