Internet Explorer 10 Preview available for Windows 7 users

Although Windows 8 users have been enjoying IE10 since the new OS launched, this is the first time Windows 7 users can give the new browser a try.

For Windows 7 users, Internet Explorer 10 won't be a major upgrade over IE9. Microsoft mainly focused on Windows 8 for this version, building a new Modern-style interface with optimizations for touch and support for Windows 8 features, such as sharing and search from the Charms bar and Start screen app pinning. Aesthetically, the desktop version of IE10 looks nearly identical to IE9.

Still, there are a few reasons to check out Internet Explorer 10 on Windows 7 devices. Let's take a look at the main new features.

Flip ahead

Internet Explorer 10 can detect when an article on the Web has multiple pages, and offers a "Flip Ahead" function to turn to the next page. It's useful if you're reading through an article and can't find the "next page" button on the website; just hit the "Forward" button in IE10's navigation bar to flip the page. This feature is disabled by default because it sends your browsing history to Microsoft. To enable it, go to Internet Properties > Advanced > Browsing and check "Enable Flip Ahead."

Security enhancements

Microsoft says Internet Explorer10 builds on the security features of its predecessor, with improvements such as full support for HTML5 Sandbox technology.

The main new feature, however, is an optional " Enhanced Protected Mode," which locks down parts of the operating system that the browser typically doesn't need to access. For instance, with this mode enabled, the browser can't access your Documents folder unless you're performing a specific action, such as choosing a file through Explorer dialog. The idea is to keep documents safe even if an attacker has exploited a vulnerability in the browser or an add-on. This feature can be enabled through Internet Options > Advanced > "Enabled Enhanced Protected Mode."

Default Do Not Track

Do Not Track is enabled by default in Internet Explorer 10. This setting asks websites not to track the user's browsing behavior for the purpose of serving targeted ads, but it's still up to those sites to actually comply with the request. Microsoft's decision to enable Do Not Track has caused a controversy, since advertisers believe users should have to opt out of tracking. As a result, some companies have said they'll ignore Internet Explorer 10's Do Not Track settings .

Under-the-hood improvements

Internet Explorer 10 is largely about performance improvements rather than big features. The browser has support for more standards-based features, such as 3D transforms, transitions and animations in CSS, and HTML5 spell-checking. Microsoft has also worked on improving JavaScript performance. Lately Microsoft has shown off its browser's performance chops with Web-based games like Atari Arcade and Contre Jour (though, to be fair, the games work well in other browsers).

To download the preview of Internet Explorer 9, head to Microsoft's website.

Firefox: back in the No. 2 seat once again

PCWorld's recent Web browser showdown may have crowned Chrome the ultimate winner, but new data suggests that Google's popular contender shouldn't rest on its laurels just yet.

In fact, after a similar market-share shift in August, Chrome fell further into third place in September, buoying Mozilla's Firefox firmly back into the second-place spot it occupied until relatively recently.

In August, Chrome claimed 19.13 percent of the desktop browser market, according to market researcher Net Applications, while Firefox accounted for 20.05 percent. Still in first place was Microsoft's Internet Explorer, with 53.60 percent.

Firefox's four-year low of 19.7 percent occurred in May 2012.

Now, for September, Firefox has increased to 20.08 percent, while Chrome has dipped to 18.86 percent. Explorer, meanwhile, gained a bit, reaching 53.63 percent.

'Critical Vulnerabilities for Months'

Of course, there's no denying that browser market share data varies tremendously with the firm that collects it--among many other factors.

Coincidentally, however, a recent report from security researcher Brian Krebs suggests that users should be wary of Internet Explorer, in particular.

"In a Zero-Day World, It's Active Attacks that Matter" is the title of Krebs' recent blog post, and he concludes that, "unlike Google Chrome and Mozilla Firefox users, IE users were exposed to active attacks against unpatched, critical vulnerabilities for months at a time over the past year and a half."

In fact, "if we count just the critical zero-days, there were at least 89 non-overlapping days (about three months) between the beginning of 2011 and Sept. 2012 in which IE zero-day vulnerabilities were actively being exploited," Krebs wrote--and "that number is almost certainly conservative."

For that same time period, however, Krebs couldn't find any evidence that malicious hackers had exploited publicly disclosed vulnerabilities in Chrome or Firefox before those flaws were fixed, he added.

'A Very Sane Approach'

Krebs' analysis comes in the wake of a recent zero-day vulnerability affecting IE.

"Microsoft was relatively quick to issue a fix for its most recent IE zero-day (although there is evidence that the company knew about the vulnerability long before its first public advisory on it Sept. 17)," but "the company's 42-day delay in patching CVE-2012-1889 earlier this summer was enough for code used to exploit the flaw to be folded into the Blackhole exploit kit, by far one of the most widely used attack kits today," Krebs wrote.

His conclusion?

While browser choice can be an emotional topic, at least "temporarily switching browsers to avoid real zero-days is a very sane and worthwhile approach to staying secure online," he wrote. "Although it is true that all software has vulnerabilities, the flaws we should truly be motivated to act on are those that are actively being exploited."