AN FRANCISCO, Feb. 15 - Bill Gates said on Tuesday that Microsoft planned to introduce this summer a new version of its Internet Explorer Web browser with stronger features to protect against viruses and other vexing security flaws that have plagued Windows users.

In a speech at the RSA computer security conference, Mr. Gates, Microsoft's chairman, said the company was making progress in its fight against spam, adding that "phishing" software scams were the fastest-growing security problem the company faced. He said the company was currently spending about $2 billion a year on computer security development and research.

Mr. Gates did not mention the Firefox browser, which is freely available and has rapidly gained users since it was introduced by the open-source Mozilla Foundation late last year. But Firefox is apparently enough of a threat that Microsoft felt compelled to rush Internet Explorer 7.0 into the market, ahead of the Longhorn version of Windows, which is not due out until 2006.

"Browsing is a vulnerability," Mr. Gates said. He said the company would make a test version of the program available this summer. "It will be another important advance," he added.

The computer security industry has generally been skeptical of Microsoft's security efforts because the company has struggled against viruses and is often blamed for the problems that plague many personal computers.

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Source: Topix