A: The built-in backup program in your iMacs, called Time Machine, doesn’t require Apple’s Time Capsule product to work. It will work with almost any brand of directly connected external hard disk.

For instance, I back up my home iMac to a Western Digital drive that’s connected to it via a cable.

As for hard-drive life, it’s my experience that many seem to die sooner or later, especially if they are used heavily. I don’t know if the ones inside the Time Capsule are especially fragile. But, in just the past six months, I’ve had an external hard disk from G-Tech die on me; seen an internal hard disk on my home Dell die for a second time; and discovered that the hard disk on my colleague’s MacBook died.

One way to protect against the failure of a local backup drive is to consider, in addition to using an external disk, backing up your data to an online backup service like Mozy, Carbonite or SugarSync.

My Dell has Microsoft Vista but I can upgrade free to the new Windows 7. However, I was told my antivirus software won’t be compatible and my email will change—the program will no longer be “Windows Mail.” What do you recommend?

A: I regard Windows 7 as much better than Vista, but you are correct that many antivirus programs will require upgrading and Windows Mail will go away during the upgrade. You’ll have to install a new email program, such as the very similar “Windows Live Mail,” which can import your messages. So, the question really is one of trade-offs. If you’re satisfied with Vista, and would rather not perform these program replacements, you should stand pat. If you don’t like Vista, and are anxious to replace it, then the hassles you describe could be worth it.

Will Office 2003 work with the new Windows 7 operating system?

A: Microsoft, which makes both products, says the answer is yes, though I haven’t tested it.

Is it possible that the Verizon Motorola Droid, which doesn’t work in Europe, could be turned into a “world phone” that could work on European cellphone networks via an app somebody might develop?

A: An app wouldn’t be able to do that for the current Verizon Droid. It’s a hardware issue.

Verizon’s Droid, like most Verizon phones, is built to run on a type of network called CDMA that isn’t used in Europe or most other countries outside the U.S., which use a network standard called GSM.

To run on these networks, the Droid, or any other current CDMA phone, would need an entirely different radio, or two radios, one for each type of network.

Verizon offers a handful of so-called “world phones,” which have both kinds of radios inside, but the Droid isn’t one of them. Motorola may well make a new model with two radios, or even a model with one radio that would work overseas, and I wouldn’t be surprised if it did so.

What could be done with an app is to allow the Droid to make so-called VOIP phone calls via the Internet.

In fact, while I haven’t checked, there may already be such an app for Android—the Droid’s operating system—that would do so. But, in many cases, making such Internet phone calls requires the user to be in range of a Wi-Fi network. Some carriers don’t allow such calls to be made over their cellular networks.

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

All of the major digital maps contain erroneous information about our street in Virginia, and don’t even show several new streets near our home that were built over three years ago. I infer that there is one source of cartography used by these Web services, and also by my Garmin navigation system. But I can’t find out what it is. How can an individual get something like this corrected?

There are actually two main companies that make the underlying maps that most of the navigation-device makers and digital-map sites use. One is called Tele Atlas (TLATF.PK), and one is called Navteq (NVT). Garmin (GRMN) uses Navteq. Each mapping company has a Web page where users can report errors or changes.

For Navteq’s error-reporting Web page, go to navteq.com and click on “Map Reporter.” For Tele Atlas’ similar page, go to teleatlas.com and click on “Report Map Changes.”

In reading your review of the new Gogo in-flight wireless Internet system, I wondered about two things: Does it support “virtual private networks,” and when will it be installed on Amtrak trains?

While I didn’t test this, Gogo’s maker, Aircell, says that VPNs, which are used by many big companies, do indeed work over the service.

As for Amtrak, the Gogo system wouldn’t work for trains, because its antennas point up, into the sky, and don’t cover ground locations like railroad tracks. However, if you are on an Amtrak train in an area where cellphone towers are near the tracks, and your laptop computer or cellphone can pick up cellular data signals, you can already surf the Web and do email and other online tasks on the train.

In fact, I happen to be writing this column on an Amtrak Acela train between Washington and New York, and, using a Verizon (VZ) laptop card, my laptop is able to access the Internet with only occasional lapses.

Because of problems I had with my computer, I lost my Internet Explorer favorites. How can I save them so I can easily restore them if they get wiped out again?

There are several methods. You should, of course, be backing up all your key data, including your browser favorites or bookmarks, regularly, either to a local external disk, or to an online backup service. That would create a fairly fresh backup of your favorites. You could also use one of several Web sites that specialize in hosting, and sharing, bookmarks or favorites. They allow you to add bookmarks to your online list as you surf, and also to upload and download the favorites and bookmarks you keep locally on your computer. The best known of these sites is probably del.icio.us, which is at http://del.icio.us.

The simplest method, however, is probably to just export your favorites to a file and save it in your Documents folder, on your desktop, or on a USB thumb drive. You can then use this file to restore your favorites in case of disaster. To do this in the latest version of Microsoft (MSFT) IE, click on the “Add to Favorites” button, select “Import and Export,” click “Next,” then click “Export Favorites” and walk through the steps that follow. Detailed instructions for all versions of IE are at: support.microsoft.com/kb/211089.

• 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.

Does any PC manufacturer offer an option to order a Windows (MSFT) PC without any extra software preinstalled?

Dell’s XPS models can be ordered without most preloaded third-party software if you are very careful about clicking all the “no” options when ordering online. But you still are likely to find yourself with Dell’s (DELL) own sometimes annoying networking software.

I have two Windows machines, one for work and one for home. Both use Outlook for email. How can I best transfer many emails from the machine at work to the one at home and still be able to read them in Outlook — without forwarding them all?

Outlook has an “Import and Export” function that will allow you to export any of your email folders to, say, a transferable medium such as an external hard disk or flash drive. You can then take this removable medium to the home computer, plug it in, fire up Outlook, and then import the folder you had exported earlier at work. You can find these import and export functions under Outlook’s File menu.

Can Internet Explorer and Firefox 3.0 coexist on the same computer?

Yes. In fact, you can have 2, 3, or 4 different Web browsers installed on the same personal computer, whether Windows or Mac (AAPL). You can even run different browsers simultaneously. For instance, as I type this, I am running IE 7, Firefox 3.0 and Safari 3.0 on the same computer at the same time.

The only slight hassle is that you will have to decide which to designate as the default browser, the one that launches when, say, you click on a link in an email.

• 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.

Last week, when you wrote about the ChaCha cellphone search service, you didn’t say how they make money. Are they collecting phone numbers from customers so they can send spam text messages, or sell the numbers to others who will do so?

ChaCha allows you to ask any Web-searchable question, by speaking it or texting it over a mobile phone, and then it sends you the answer via text message. The company charges consumers nothing, but says it is hoping to make money by striking deals with cellphone carriers to incorporate the ChaCha service into their current 411 phone-number look-up services. Also, it hopes to eventually include ads in the text message answers it provides.

In addition to the message that includes the answer, ChaCha sends you a message saying it is working on your request and restating your question, so you can see if it understood you correctly. It also sends an introductory text message to first-time users and occasional tips on how to use the service. Scott Jones, ChaCha’s chief executive, asserts that “we do not spam” and “we never make phone numbers and/or email addresses available to others.” He said the company is updating its privacy policy to make that clearer.

We have DSL service. I use several Web-based applications, one of which is online backup, and my husband is concerned that they degrade his use of the Web, which includes creating Web sites. I contend that that is like saying turning on one light bulb is using too much electricity, that two people on one DSL line aren’t using up too much bandwidth. Who is right?

Every situation differs, depending on exactly which programs you are each using, how you have them set, whether you are using them simultaneously, and how fast your DSL connection is. However, in general, your husband is correct that it is possible for heavy Internet usage on one computer in a home to slow down Internet speeds on another.

This is especially true with something like online backup, because it relies on your DSL account’s upload speed, which is typically far slower than the download speed. If your online backup program is trying to push a bunch of files over a slow upload connection, while he is in another room trying to upload new versions of a Web site over the same narrow upload pipe, it could affect the speeds he gets. You might try coordinating or staggering those online activities that involve heavy uploading. Normal Web surfing or emailing shouldn’t require any such coordination.

I am thinking about purchasing a Dell (DELL) XPS One all-in-one desktop, but I have one question. Does the Dell’s built-in TV tuner require any extra attachments to watch TV right out of the box?

You can watch over-the-air stations and analog basic cable stations right out of the box, without added equipment. However, you may want to connect a small desktop antenna to improve reception, which is what I did when I tested this machine. To use the XPS One with digital or premium cable or satellite stations, you would have to connect it to a cable or satellite receiver, just as most people do with their TV sets. This requires the use of an adapter that comes with the machine.

• 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.

Has anyone come up with a method that allows people to take pictures with a regular digital camera and then download them wirelessly to a computer, and/or perhaps to the Internet?

There have been a few digital cameras with built-in Wi-Fi wireless capability, but the best and simplest method I know is a $100 product called Eye-Fi. This tiny gadget looks and works like a regular, garden-variety SD memory card, but it packs a Wi-Fi transmitter inside. It fits into a standard SD memory-card slot and is compatible with a wide range of camera models from Canon (CAJ), Kodak (EK), Nikon (NINOF.PK) and others.

Coupled with clever software, and a clever Web site, the Eye-Fi card automatically zips your pictures wirelessly to your PC or Mac, and/or to your choice of over 20 online photo-sharing services.

For more information, see www.eye.fi. For a list of compatible cameras, see support.eye.fi/compatibility/. For a full review of the product, see: solution.allthingsd.com/20071121/.

You mentioned last week that SugarSync might be a good solution for backups, so if one computer dies your files still exist on another system. But what if the doomed computer doesn’t actually die but its files are corrupted by malicious software? Do those newly corrupted files overwrite the good copies on your SugarSync network?

They could do so, depending on which folders you had chosen to replicate on your other computers. Automatic-synchronization services like SugarSync have a tough time telling whether changes to a file are deliberate, accidental or the result of some sort of corruption. Though the last is rare, it could look to SugarSync like you had changed the file on purpose.

One way to guard against that is for a service to offer “versioning” — the practice of maintaining multiple past copies of a file. That way, if a change isn’t intentional, you can go back to the prior, pristine version. Sharpcast, the company that makes SugarSync, says it is planning to add versioning to the service, but offers no specific date. In the meantime, one way to back up a file without fear of its being overwritten by a corrupted version is to upload it to SugarSync’s special “Web Archive” folder, whose contents are never automatically updated.

Have you ever reviewed and suggested a media player for connecting to a home theater to play all songs, videos and photos that exist on your home computers?

Yes, I have reviewed several over the years. The one I find simplest and best designed is Apple TV, which, despite its name, can work fine in a household with no other Apple (AAPL) hardware. It costs $229 and is a small, thin, unobtrusive box that fetches music, photos and videos from your home network using either a wired or a wireless connection. It can connect to your TV set or home theater via a variety of analog and digital ports, including component-video, HDMI, and optical and analog audio. It supports high-definition video and works with any computer, Windows or Mac, that has Apple’s free iTunes software installed and running.

Apple TV handles many standard photo, music and video formats, but it is limited to music and video files that iTunes can handle. That excludes copy-protected files in Microsoft’s formats, and certain open Microsoft formats, but includes common files like MP3s. Apple TV also allows you to access YouTube and to purchase music and TV shows from Apple, and rent movies from Apple, without the use of a computer.

• 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.

I have a 3-year-old PC, which has a single physical hard disk divided into a small C drive that is almost full and a larger D drive that has lots of empty space. I know I can move stuff from C to D, but how can I either merge these hard drives or somehow make D the automatic destination for files I download?

You can merge the drives into one larger C drive, or redistribute space between them, by using what’s called a disk-partitioning utility — a program that rearranges the space on the hard disk without erasing your files. One I have tested and found that works well is called Partition Magic and is sold by Symantec.

Short of doing that, you can change the settings in programs you use to download or save files so that they store the files on your roomier D drive. Not every program has such a setting, but many do. These settings are usually found in the options or preferences sections of the software. For instance, in the latest version of the Firefox Web browser, go to the Tools menu, select “Options,” and, under “Main,” in the Downloads section, you can specify a folder on your D drive where it says “Save files to.”

In your review of the Amazon Kindle e-book reader, you praised its ease of downloading books, but criticized the hardware design. You seemed to prefer the design of the Sony Reader, which costs $100 less, but said it offers fewer books. If you had to choose between them, which would you pick?

Neither is a compelling product. However, putting aside price as an issue, I would choose the Kindle, despite its design problems. The Sony is slimmer, sturdier and, unlike the Kindle, it isn’t prone to accidental button-pushing. But Amazon’s device can download books directly, without the need for a PC. Sony’s can’t. And Kindle’s online catalog of compatible titles is 90,000 books, more than triple the number Sony offers.

Unless you absolutely crave an e-book reader now, I’d suggest waiting for a system that’s better than either. However, if you’re going to invest $300 or $400 now in a device to read electronic books, you would likely want the one with the widest selection of titles and the quickest, easiest downloading process. And that’s the Kindle.

I use Outlook Express for my email. I have been getting a lot of offensive junk mail I’d rather not even view for a moment. Is there a way to delete incoming mail in Outlook Express without having to first view the contents?

You can avoid automatically viewing the contents of your email in Outlook Express, and many other email programs, by turning off the preview feature. In Outlook Express, click on the View menu, then select “Layout…”, and uncheck “Show Preview Pane.” Then, click OK. After that, you will have to manually open each message to view its contents.

However, you may have to open some emails anyway in order to decide whether to delete them, since spammers often use deceptive sender names and subject lines that make it hard to decide if they are worthy of deletion. So, you might consider installing an antispam program.

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

I currently spend about $50 to $60 per year for Norton Security software. Is this necessary when Windows XP has its own security built into the operating system?

Windows XP doesn’t include antivirus or antispyware programs, so you definitely need some sort of add-on security software. If you don’t want to pay for it, there are free alternatives available.

How do we determine when to purchase a new PC? Our current Dell is about five years old. I’m feeling a little worried because I have my music and photos on the computer and don’t want to lose them.

There’s no universal answer to your question. In general, I don’t believe people should replace computers that are working well for them just because they reach a certain age. On the other hand, five years is pretty old for a PC. At that age, the odds increase that the hard disk may develop problems, and that newer versions of the software you like will require hardware upgrades that may cost more than you want to invest in an older machine.

Assuming your Dell is working fine, that you aren’t a power user, and that your music and photo activities are simple and basic, there’s probably no urgent need to replace the PC. But, to assuage your concern about “losing” your pictures and music, you might back up those precious files to an external hard disk or an online backup service.

Last week, you compared the start-up time of Windows Vista to Apple’s new Leopard operating system, and found Vista to be much slower. But you used different laptops for each. What would the numbers be on the same Macintosh running the two operating systems?

I ran the tests again on a single computer, a fairly new Apple iMac, which can be started up, and restarted, in either Vista or Leopard. I used the Mac’s Boot Camp feature, in which only one operating system is running at a time, has its own dedicated portion of the hard disk and fully controls the hardware. The machine uses an Intel processor and other key components commonly found on Windows machines, and runs Windows just like a Dell or any standard Windows PC, without any involvement from the Mac operating system.

This Vista installation doesn’t include any of the speed-robbing trial software commonly included by PC makers, though it does have security software from Symantec. However, the test results were very similar — Leopard started and restarted much more quickly than Vista did.

In this simple test, I timed both operating systems from a cold start and a restart until the computer was fully ready for operation, with the hard disk quiet and the network connection established. The cold start, beginning with the computer completely off, took Leopard 46 seconds, but took Vista one minute and 42 seconds. A restart, beginning with the computer running an email program, the Firefox Web browser, and Microsoft Word, took one minute and two seconds for Leopard, and three minutes and 17 seconds for Vista.

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

I can’t figure out how to remove a song from my iPhone. How do I do it?

Unlike an iPod, the iPhone has no purely manual-mode option, which would allow you to drag songs on and off of it. However, there are alternative methods.

The simplest approach is to connect your iPhone to your Windows PC or Mac, and allow it to synchronize as usual. Then, select your iPhone in the list at the left edge of the iTunes window in order to bring up the iPhone-settings functions in the large window at the right in iTunes. Click on the Summary tab, and check the option called “Only sync checked items.” This will limit the songs and videos the computer places on the iPhone to those for which you have checked the little box that appears next to their names in iTunes. Next, go into your music library, or into any playlists you have selected for syncing with the phone, and uncheck any songs you no longer want on your iPhone. The next time you perform a sync, these songs will be removed from the phone.

Another method is to place all the songs you want on the iPhone into a single specially designed playlist, or several such playlists. Then, go to the Music tab in the iTunes settings screen and click on “Selected Playlists.” Next, check off only your special iPhone-bound playlists. Once this is done, you can control which songs are, or aren’t, synchronized to the iPhone by adding or removing songs from these playlists. If you remove a song from one of these playlists, it will be deleted from the iPhone the next time you perform a sync.

Neither of these methods will delete the songs from your computer or your iTunes library, or prevent them from playing on your computer.

I have tried to download some pictures recently and use them as wallpaper. I am storing them in my My Pictures folder. But, when I choose to make them my wallpaper, they appear multiple times on my desktop. How can I have a picture cover the whole background on my monitor?

Assuming you are using Windows XP, go to the Display control panel and select Desktop, then find the image in the Background list and select it. Then, under Position on the right, select Center or Stretch. Note, however, that if you have downloaded a small image from the Web, and your monitor has a relatively high resolution, the Center option won’t allow the image to fill much of the screen. The Stretch option, while filling the screen, may result in a grainy and/or distorted image.

I was wondering if you could recommend a good service for automated online backup of a PC running Vista. All the services I have found require the user to manually transfer files to the online site. In my ideal world, I could set up my machine to transfer the files during the evening.

There are two automated online backup services I’ve tested and reviewed, Mozy (mozy.com) and Carbonite (carbonite.com).

Both work on Vista, neither requires manual file transfers, and both are good, though I preferred Mozy when I last tried them in December 2006. However, Carbonite has released a new version I haven’t tried yet, and Mozy has also been updated since then. I don’t think you’d go wrong with either. You can read my review at ptech.allthingsd.com/20061214.

Mozy offers two gigabytes of backups free, and charges $4.95 a month for unlimited backup, though you can save by paying one year or two years in advance. Carbonite offers a 15-day free trial, after which you pay $50 a year for unlimited backup, though you can save if you pay upfront for two years.

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

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