Q I'm concerned about software bugs in new programs. When do you recommend people begin using the new Firefox 3 Web browser?


A Try it now. Since Firefox 3 was introduced in June, the reviews have been favorable. CNet, PC Magazine and InfoWorld all gave it top ratings as a Web browser, even though it still trails Internet Explorer in total number of users. About 28 million free copies have been downloaded since June, said Firefox's developer, the Mozilla Foundation.

One big advantage of Firefox 3 is that it uses fewer PC resources.

That's good news if you've been in my position and had an earlier version of Firefox compete with other programs for a PC's random-access memory. That in turn bumps up demands on the processor chip, because a full memory means more information must be shifted back and forth to the hard-disk drive. The net effect is that the processor is swamped and the computer is nearly paralyzed.

So far, Firefox 3 appears to use about 30 percent less memory than Firefox 2.0 when both are idle.

A new security feature in Firefox 3 blocks the display of a phony Web page (it checks a website's digital certificate, which identifies the Web page owner and is hard to fake). Bogus websites typically are used in "phishing" schemes that try to steal passwords or credit card numbers.

Q My Macintosh computer has been able to read Microsoft Word documents using its 2001 version of Word. But I can't open documents written in the new Word 2007 program, which creates file with a .docx suffix instead of the familiar .doc. Is there a program I can use to read Word 2007 documents, or will I have to buy a new copy of Word?


A There are free, downloadable programs that allow you to view Word 2007 documents, but your Mac software may be too old to use one. If you want to try, search the Apple website for "Microsoft Office Open XML File Format Converter 1.0".

Windows users with the same problem can search the Microsoft website for the free "Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats." To use it, you need either an earlier version of Microsoft Office or the additional download of Microsoft's free "Word Viewer."

If you want Word 2007 files you create to be compatible with earlier versions of Word, use the "save as" function, go to "save as type" and pick "Word 97-2003 & 6.0/95-RTF."

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