Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability.

I have a PC with Windows XP, which I bought because my computer guru said to stay away from Vista. I read your column saying upgrading from XP to the new Windows 7 will be much more cumbersome than doing so from Windows Vista. So, what should I do now? Upgrade to Vista for a while so I can then move more smoothly to 7? Or wait, buy a separate Windows 7 computer in the fall, and just transfer my files and applications from the XP computer?

Putting budget considerations aside, I think the latter course would make more sense. The new machine with Windows 7 preloaded will probably give you smoother performance than one you upgraded twice to new operating systems in a matter of months. But, bear in mind that you will have to reinstall all your applications on the new Windows 7 computer, and that, depending on the terms of the applications’ licenses, you might even have to buy new copies. On the other hand, if you do the chain of upgrades, and don’t buy a new machine, you may be able to avoid this application problem, or at least much of it.

I appreciated your review of the Clickfree automatic backup drive. Does the backup it creates include the various folders and subfolders for data such as photos, or does it just create a huge single list?

The Clickfree software is primarily designed to back up, display and restore your files by their types — photos, music, text, email, spreadsheets, etc. Once it has performed a backup it lets you view and restore your files by these types. However, it will display the tree of all your folders and allow you to specify where it should search for these files. It also allows you to back up and restore entire folders, such as your My Documents folder, regardless of their contents. Detailed information, including a downloadable user manual, is available in the Support section of clickfree.com.

I am planning to buy one of the products you recently reviewed — a Western Digital My Book — and attach it directly to a port on my Internet router. Can I install antispyware and antivirus programs on the drive? If not, how will the data on this drive be protected?

Nothing is perfectly secure. The bad guys are clever, and you never say never. However, since this product isn’t an actual PC running Windows, viruses and spyware programs can’t likely run directly on it. Still, if one of your computers contains malicious software, and it can see the contents of the network drive, then the data on the drive could be endangered. I know of no way to install or run security programs on the drive. But the security software on your PC may protect the drive, if it is able to handle external drives across a network. Also, the firewall built into your network router will help. The product has some security measures built in, such as encrypting files when you use the optional feature that allows you to access the drive’s contents across the Internet.

• You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

I saw your recent review of ICE, the emergency medical information app for the iPhone. But my iPhone is set up to require a passcode to get to the home screen and run apps. Is there any way to display emergency contacts before a person enters the passcode?

There are some apps that allow you to customize the wallpaper of your iPhone or iPod Touch by adding a few lines of text that can be seen before it’s unlocked. One, called Close Call, displays a red cross and, next to it, an emergency phone number, and one brief line about, say, a key allergy or medical condition. The app is free, and is from a company called Polka, at polka.com.

I installed VMware Fusion on my Mac so I can run a virtual Windows XP computer on the Mac. When in the virtual Windows environment, I use security software. If I have the Fusion program shut down completely when I am not using it, will my computer be vulnerable to Windows security threats?

The vast majority of viruses, spyware and other malicious software is designed to run on Windows and cannot run natively on the Mac’s built-in operating system. So, while you are wise to use security software in your virtual Windows PC, any malware it misses won’t be able to run when Fusion is shut down. While even a virtual PC can get real viruses, this faux PC just disappears when Fusion is shut down, and so does all its software, including viruses.

But simply because Windows-based malware can’t run on the Mac’s OS, that doesn’t mean you don’t have to be careful. You can still be tricked by false email and Web sites into giving up personal information.

• You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

In the new version of Microsoft Office, I cannot find a “favorites” capability in the Open dialog box. In my older version, when I began to open a document, I had a box on the left called “Favorites” that I could invoke to find common file locations. Did they really kill this very useful feature?

No, but they changed the way you make it visible in Office 2007. You can get back your “Favorites” category by right-clicking the bar at the left-hand side of the Open dialog. From the menu that appears, click on “Add Favorites,” and your Favorites category should appear in the left-hand bar, and stay there.

If I have McAfee security software, do I need an antispyware program as well?

Everyone running a Windows computer, even a virtual Windows computer on a Mac, should have antispyware software. In some ways, spyware is a worse security problem than viruses, and can lead to identity theft.

McAfee has made many types and versions of security software over the years. Some, especially recent versions of the company’s comprehensive products, include antispyware protection. Check your version to make sure it includes this capability. If it doesn’t, you will either need to upgrade to a more comprehensive suite, or obtain a separate anti-spyware product.

When my friend put a Spike Jones CD of mine into his Mac to import it using iTunes, the CD was misidentified with an embarrassing title. What would cause such a thing to happen? Does iTunes go out to the Web looking for album names, instead of going by what’s on a disk?

Yes. Music programs like iTunes, and all its major competitors, can’t identify a disk directly. So they rely on online databases to identify CDs. Each CD contains a hidden code that the database providers quickly match up with their huge catalogs of CDs to provide the album title, artist, date, track list and other information. But, sometimes, especially when the CD is relatively obscure, the databases are wrong and yield erroneous information. When that happens, you have to type in the information by hand.

You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

I have moved from a PC to the iMac. In the Windows environment, I felt a need to run utilities to clean out the registry and defragment the hard disk frequently. Is this also needed on the iMac? If so, what programs are recommended?

The Mac operating system, called OS X Leopard, doesn’t include a registry, which is a feature of Windows that holds information that programs need to operate properly. So there’s no need to clean or maintain any registry on a Mac.

Mac hard disks, like those on Microsoft (MSFT) Windows computers, can get fragmented — a condition in which parts of files are so scattered around on the disk that the disk runs slowly. However, the operating system has some under-the-covers features that generally obviate the need to run a defragmentation utility. In fact, Apple (AAPL), which calls defragmenting a disk “optimizing” it, flatly claims that “You probably won’t need to optimize at all if you use Mac OS X.” There are some Mac defragmentation utilities, but I don’t believe you will need them unless you have large numbers of extremely large files and almost no free disk space.

My son’s computer frequently gets infected with adware, pop-ups. Recently it was hit with a continuing pop-up ad called VirusHeat that touted itself as a solution to the computer’s problems. When I paid for VirusHeat, the problems went away. Is it legitimate?

According to numerous reports on the Web, including some from security companies, VirusHeat is a form of malicious or misleading software. It falls into a category that attempts to scare people into thinking their computers are badly infected, or exaggerates any problems you may have. This is a common tactic now used by creators of malware.

Some of these fake or misleading “security programs” may be designed merely to make you pay. Others may even be designed to install the very kinds of viruses, spyware or adware that they claim to fight.

I have updated to a new PC. My data are on a floppy disc. There is no floppy disc drive on this new computer. How can I transfer my data?

For around $25, you can buy an external floppy disk drive that plugs into a new PC using its standard USB port. If you do so, and connect it to the new PC, you should be able to copy your data to the new computer’s hard disk.

• You can find Mossberg’s Mailbox, and my other columns, online for free at the new All Things Digital web site, http://walt.allthingsd.com.

We are connected to Comcast (CMCSA) cable and use no antennas. Will we need one of the government-subsidized converter boxes next February?

Not if you are using a cable set-top box, like the vast majority of cable customers. If you are one of the minority of cable households whose TVs use an internal cable tuner, you may need a converter box. To be sure, contact your cable company or TV manufacturer.

In your laptop buying guide last week, you recommended buying a machine equipped for the “n” type Wi-Fi of wireless router. I was under the impression that this has not yet been standardized. Is that wrong?

The engineering committee that has been debating the standard for years has not yet completed its work, but the market has simply moved ahead on its own. This new, faster version of Wi-Fi is being built into routers, computers and other devices by nearly every major manufacturer. In my limited tests, I have found no compatibility problems, and it is backwards compatible with the older “g” and “b” standards.

Is the Mac immune to viruses? If not, do you have a recommendation of the type of antivirus software one should procure and load onto a Mac?

No personal computer or personal computer operating system of which I am aware is “immune” to viruses, spyware or other malicious software. That includes Apple’s (AAPL) Macintosh and its operating system, Mac OS X Leopard. Hackers have demonstrated the ability to invade the Mac. However, there are only a handful of viruses or other malicious programs for the Macintosh that have successfully spread beyond the lab. And these have harmed only a small number of actual users.

Of the well over 100,000 known viruses, spyware programs and other malicious software applications that are about in public, all but this handful are written to run on Microsoft (MSFT) Windows, and cannot operate on the Macintosh OS. For that reason, I don’t believe Macintosh owners need security software, unless they install and run Windows on their computers. If they do run Windows, Mac owners are well advised to purchase and install Windows security software to protect the Windows portion of the machine.

Having said that, I do not mean that Mac owners should be blind to security threats that don’t involve viruses or spyware. Just like Windows users, Mac users can succumb to what is called “social engineering” — scams and schemes that operate via email and Web sites that are often authored by crooks but made to look official. So, like Windows users, they must be on their guard.

You can find Mossberg’s Mailbox, and my other columns, online free at the All Things Digital web site, http://walt.allthingsd.com.

Do I need antivirus or antispyware software on a Macintosh running the Leopard operating system?

The Macintosh isn’t inherently invulnerable to malicious software. In fact, last week it was reported that there is a new scam on the Web that can plant a malicious “Trojan horse” program on the Mac. However, this is a rare event. There have been practically no viruses, spyware or other malicious programs written for the Macintosh that have actually spread outside the laboratory.

For that reason, most Mac users don’t run security software, and security software companies don’t make much of an effort to sell it for Macs. I don’t believe it is necessary, so far, for all except the most paranoid (and those who run Windows on their Macs). In fact, freedom from the burdens of running and updating security software has been one of the Mac’s big advantages.

Even the new Trojan Horse apparently relies on tricking the user, rather than on sneaking through holes in the Mac operating system. According to reports, to get infected you must go to a pornography site, and agree to download a program allegedly needed to view the porn. Next, the Mac will require that you type in your administrator ID and password to complete the installation, thus agreeing to install the program a second time. If you do all that, you get a program that supposedly redirects your Web browser to bogus Web sites. My advice: even if you frequent porn sites, don’t agree to download any programs from them (that goes for Windows users as well).

Some interpret the appearance of this new Trojan Horse as a sign that the Mac’s increasing market share will begin to attract a flood of viruses and spyware, and that Mac users will soon have to start running security software. If it happens, and the threats are more insidious than the latest one, I will be ready to change my recommendation. But not yet.

In reply to a question last week, you mentioned that there are free security programs available for Windows. Could you please suggest where to download such alternatives?

There are a number of them, but ones that I like are free, basic antivirus and antispyware programs called AVG from a company called Grisoft, which also makes more elaborate security software. You can download these programs at free.grisoft.com/doc/5390/us/frt/0.

I don’t have Microsoft PowerPoint but I occasionally get PowerPoint files as email attachments. Somewhere I read that one can download a free PowerPoint program so you can read these files. Can you help me with this, please?

I don’t know of any free versions of PowerPoint, but Microsoft does offer a free program that will let you view, but not create or edit, PowerPoint files. You can download it here.

You can find Mossberg’s Mailbox, and my other columns, online for free at the new All Things Digital Web site, http://walt.allthingsd.com.

Write to Walter S. Mossberg at mossberg@wsj.com

Apple makes beautiful hardware, and, in my experience, it runs Windows quite well. In fact, the mouse and keyboard problems you cite are easily overcome, since you can plug almost any USB keyboard and mouse made for Windows into a Mac and they will work fine, right-mouse button and all.

However, what makes a Mac a Mac is primarily Apple’s OS X operating system, and the software Apple bundles with it, the iLife suite. If you don’t intend to use that, I don’t see much point in buying an Apple computer. You won’t get the advantage of the Mac’s lack of viruses and spyware, which stem from the operating system, not the hardware. And you can buy a Windows computer for less than the least expensive Mac.

In my view, the main value of the Mac’s ability to run Windows is that it allows Apple owners to use the few Windows programs they require or prefer that lack Mac equivalents, while primarily running the Mac operating system and programs designed for it.

How can one send an email to a group of people without all of their individual email addresses showing?

The most common method is to put your own email address in the “To” field and the names of all the recipients in the “Bcc” field, which is designed to be invisible. There’s always a danger someone quickly scanning just headers will decide not to read the email, since it isn’t addressed to her, but most email veterans understand the technique.

Is there a way to regain the traditional drop-down menus and other interface items in the new, redesigned Microsoft Office 2007?

There is at least one third-party add-in program designed to do this, but I haven’t tested it. It’s called Classic Menu for Office 2007, and can be found at www.addintools.com.

You can find Mossberg’s Mailbox, and my other columns, online for free at the new All Things Digital Web site, http://walt.allthingsd.com.

Write to Walter S. Mossberg at mossberg@wsj.com

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about accessing financial sites on a nonsecure Internet connection, which cellphones with email capability to take abroad, and what to do about Web sites that don’t work well in Safari.

I am concerned about security on my laptop when traveling and using nonsecure Internet connections available at motels. Is there a way to be secure when accessing my financial Web sites while using a motel’s connection?

You can install a good firewall, and sweep your laptop with security software for spyware and other malicious software that might transmit passwords. And you can make sure you are using antiphishing software. Better yet, you could use a sort of private Internet tunnel, called a Virtual Private Network, or a remote control service, like GoToMyPC, so you are actually using your home PC — remotely — to contact the Web sites involved.

But, the bottom line is that, unless you are on a network that you can control and secure, such as a home or office network, I wouldn’t advise accessing financial accounts online, or performing financial transactions. I wouldn’t trust sensitive online transactions to any public Internet connection, such as those at motels. There are too many people, including other guests, the motel staff, and the people at the company that provides the motel’s Internet service, who could potentially be watching what you are doing.

Is there a cellular phone that can be taken abroad that has a good email capability, for a comfortable price?

That depends on what you’d consider “good” email capability, or what price would be “comfortable” for you. It also depends on what countries you’re heading for. But, in general, any BlackBerry or Treo that works with the AT&T (formerly Cingular) or T-Mobile networks here in the U.S. will work in Europe and in many other regions. And both have what I consider good email capabilities for the price, which can vary, depending on model, and be as low as $99.

In general we love our new MacBook laptop, but there is one thing we’re not sure how to work around. We find that there are some Web sites that don’t seem to work well with the built-in Safari browser, and on some sites, we are unable to play a video. Is there a solution?

Yes. For the Web pages that don’t work well with Safari, you can download and use as an alternative the Firefox browser, which comes in a Mac version that is essentially identical to its Windows version. You can get Firefox, which is free, at mozilla.com.

The videos that won’t play were likely produced in the latest version of Microsoft’s Windows Media format. Microsoft offers free software that allows these videos to play on a Mac. It’s called Flip4Mac and can be downloaded at: www.microsoft.com/windows/windowsmedia/player/wmcomponents.mspx.

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Because of the volume of email I receive, I can’t routinely answer individual questions by email, or consult on individual problems or purchasing decisions. I read all questions I receive and select three each week to answer in the column.

Write to Walter S. Mossberg at mossberg@wsj.com

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained questions about using Microsoft programs on the Apple iPhone, dividing software between a Mac and a PC and finding a video-conferencing service compatible with both operating systems.

Will the new Apple iPhone be able to open and edit Microsoft Word documents? Will it be able to synchronize calendar and contact entries with Microsoft Outlook?

These and many other questions I received about the iPhone are good ones. But they can’t be answered yet. The iPhone won’t be on the market until June, and its software isn’t complete. Apple did say the phone would be able to synchronize calendar and contact entries with Windows computers, but didn’t specify which Windows programs would be supported. As for Word documents, Apple said nothing about this, but I wouldn’t rule it out. And remember, as with the iPod, the iPhone will be upgradeable with new features through Apple’s iTunes program.

I am a Windows user who would like to buy a Macintosh but still keep my PC and work in both systems. Is there any way to avoid bankrupting myself by buying the same software on both systems?

Sure. Just use the machines for different purposes, and keep each stocked only with the software for those purposes. For instance, because it suffers from essentially no viruses and spyware, you might use the Mac for Web surfing and emailing — through its excellent built-in software — and dedicate the older Windows machine to software that’s available only on Windows, or where the Windows version beats the Mac version, such as Quicken.

The Mac comes with a much richer collection of bundled software than a typical Windows PC does. For instance, its included iLife suite includes photo, video, music, Web-site creation and DVD-burning software that are hard to match on Windows, even if you spend extra. The new Windows Vista closes this gap some, but not completely. And the Mac has lots of nice little touches. For instance, without any additional software, a Mac can save any document or Web page as an Adobe PDF file, readable by any computer.

On the other hand, Windows offers many more niche or specialty programs, such as small-business software, and programs such as WordPerfect and Microsoft Access that some businesses and professional firms rely upon. And Windows kills the Mac on games.

The only software you might need to replicate on both platforms is Microsoft Office, which comes in versions for both. You can buy the Mac version for about $150.

I have just become a grandmother, but my granddaughter is a continent away. I would love to use Web cams to watch my granddaughter grow up, but my computer uses Windows and my daughter uses an Apple. Any suggestions for a video service that is compatible with the two systems?

Yes. Try SightSpeed, a very nice video-conferencing service that works on both Windows PCs and Macs. It can be downloaded at www.sightspeed.com.

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Because of the volume of e-mail I receive, I can’t routinely answer individual questions by e-mail, or consult on individual problems or purchasing decisions. I read all questions I receive and select three each week to answer in the column.

• Write to Walter S. Mossberg at mossberg@wsj.com

Here are a few questions about computers I’ve received recently from people like you, and my answers. I have edited and restated the questions a bit, for readability. This week my mailbox contained a question about security software for Macs.

If you have a question, send it to me at mossberg@wsj.com, and I may select it to be answered here in Mossberg’s Mailbox.

There’s been a lot of press lately about increased virus activity on the Macintosh platform. Should Mac owners now be running the same kinds of security software that Windows owners use?

There is no sudden security crisis on the Apple Macintosh platform. In fact, for average Mac users, there isn’t a security threat of any significance, at least not yet. It is laughable to compare the real, massive and burdensome security problems on Windows with the largely theoretical security problem on the Mac.

As I have said in the past, no operating system is invulnerable to attack, including Apple’s Mac OS X operating system, which powers Macintosh computers. It is possible to write malicious software for the Mac, including viruses and spyware, and it is possible for this software to spread in the wild, infecting many Macs.

However, despite what you may have heard, this hasn’t happened to any degree that matters, yet. As of today, there have been exactly two documented, successful pieces of malicious software — viruses, trojan horses, worms — that affected users of the Mac OS X operating system, since it was released in 2001. And these two failed to spread much, affecting probably a few dozen people, and doing no harm. I expect there to be a small number of additional Mac viruses this year.

By contrast, there are over 100,000 reported viruses for Windows, some of which have affected millions of people and have done significant economic damage. As for spyware, I know of no documented cases on Mac OS X, while there are certainly thousands on Windows. These Windows viruses and spyware can’t run on the Mac operating system, even on Macs powered by the same Intel processors used by Windows PCs.

The recent publicity concerns theoretical vulnerabilities that security firms have identified in Apple’s operating system. These vulnerabilities, like similar vulnerabilities in Windows, aren’t necessarily being exploited. Like Microsoft, Apple fixes vulnerabilities as they are identified. But some critics say Apple does this too slowly.

Security firms are saying that the discovery of these vulnerabilities in the Mac has increased sharply lately. They say that based on past patterns, this should yield a sharp increase in the number of Mac viruses in coming years. But even a “sharp” increase could well mean under 50 viruses by 2008.

So my advice to Mac users is that at the moment, I see no reason to buy and run security software, which is in itself costly and can degrade your computing experience. But you should make up your own mind, based on your tolerance for risk.

Here’s a test you can use. Imagine you live in a neighborhood that has suffered only a couple of ambiguous, harmless burglaries over five years, even though the neighborhood is surrounded by much higher-crime areas. If you would buy a burglar alarm in such a neighborhood, then buy Mac security software. Otherwise, don’t. Just turn on Apple’s built-in firewall and relax.

There is one exception: If you are running Windows on one of the new Intel Macs, you are just like a Windows user, and you must run Windows security programs when using Windows.

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Because of the volume of e-mail I receive, I can’t routinely answer individual questions by e-mail, or consult on individual problems or purchasing decisions. I read all questions I receive and select three each week to answer in the column.

Write to Walter S. Mossberg at mossberg@wsj.com