Apple has revised the way it sends software updates to Windows PCs via its Software Update service in response to charges that it was sneaking its Safari Web browser onto users' desktops without their permission or knowledge.

The latest version of the Software Update tool for Windows, version 2.1.0.110, now clearly lists software that can be downloaded via the service and groups the updates into those for applications already on the user's computer and updates for new software.

The new version of Software Update also gives users the ability to turn off the service.

In modifying Software Update, Apple was clearly responding to widespread criticism that the service downloaded Safari 3.1 onto users' systems surreptitiously.

The company included the browser as a stealth update for users of the Microsoft (NSDQ: MSFT) Windows versions of its iTunes and QuickTime software. Mozilla CEO John Lilly likened the strategy to tactics used by hackers to insert malicious code into downloads.

"Apple has made it incredibly easy -- the default, even -- for users to install ride along software that they didn't ask for, and maybe didn't want," said Lilly, in a recent blog post. "This is wrong, and borders on malware distribution practices."

Safari competes with Mozilla's Firefox product in the Web browser market.

Safari 3.1 has been hit with other problems since it launched in March.

Researchers at software security firm Secunia last month reported finding two "highly critical" vulnerabilities in the browser.

In one instance, files with long names downloaded via the browser "can be exploited to cause memory corruption," according to Secunia. That could result in the host computer becoming vulnerable to arbitrary code execution -- a situation where intruders can remotely execute commands on the targeted machine.

The other vulnerability lets hackers display their own content in pages loaded into Safari 3.1 without changing what's displayed in the browser's URL address bar.

There's also been reports that Safari 3.1 tends to crash on computers running Windows XP .