I haven’t tested campusbackup.org, whose Student Backup service copies an unlimited quantity of word-processing, spreadsheet, presentation and PDF files, once nightly, to a remote server for $50 a year. But there are other, more versatile options I have tested that, unlike Student Backup, copy photos and music and other types of files. These include MozyHome ($4.95 a month for unlimited storage, at mozy.com) and Carbonite ($55 a year for unlimited storage at carbonite.com). All three work with either Windows or Mac computers.

I read that importing the newly remastered Beatles CDs into iTunes and listening to them on a computer or portable player is like buying a masterpiece and staring at a photocopy of it. Any truth to this? Does importing really lose that much quality?

It depends on how sensitive an ear you have. In most cases, when you import a CD into iTunes or any other software jukebox program, you are converting the songs into a compressed file, such as an MP3 or AAC file. This saves a ton of space on your hard disk, but at least subtly diminishes quality. To an audiophile, that can make a big, negative difference, especially when you add the insult of listening to the music through iPod headphones or small computer speakers. To most of the rest of us, though—especially with rock, pop, urban or country music—it’s no big deal.

However, there is a compromise. If you don’t care about the songs taking up lots more space on your hard disk, iTunes will allow you to import them in a much less compressed format called Apple Lossless or an uncompressed format called WAV. You can choose which format to use in the iTunes Preferences settings. In the latest version of iTunes, called iTunes 9, this particular option is found under the General tab in Preferences, by clicking on the button called “Import Settings.”

Previously I had a Dell and Windows and used Family Tree Maker for genealogy records. Now that I’m an Apple owner, I find that Family Tree Maker does not work on an Apple, only Windows. What can I do about this?

It seems to me that you have three obvious options. If you still have your old Dell, you could crank it up again just for the purpose of running Family Tree Maker. Or, you could buy a boxed copy of Windows and install it on your Mac, which is fully capable of running Windows and Windows programs (assuming it’s an Intel-based Mac). Finally, you could switch to one of the native Mac-based genealogy programs and import your data from Family Tree Maker via the standard GEDCOM file format used in genealogy. One such program, called Reunion, includes specific instructions on importing data from Family Tree Maker on its “Top 10 Questions” page, at leisterpro.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.

Yes, you are correct. Snow Leopard is the first Apple OS version that runs only on Intel-powered Macs, and your iMac runs on the G5 processor, which isn’t an Intel chip.

As for the comparison with Microsoft’s policy: In one way, Apple’s approach is much worse. It is totally cutting off some of its user base from the new OS, including some folks with machines as little as 3 years old. Microsoft isn’t making it impossible for XP owners to move to Windows 7— it’s merely making it so painful, tedious and complicated to upgrade that many non-techies who want Windows 7 may give up and feel compelled to buy new PCs. On the other hand, Apple’s policy affects a smaller proportion of its customers. Only about 20% of its users still use older, non-Intel-based Macs. By contrast, Microsoft’s policy affects a much greater percentage of Windows users, since, despite its advanced age, Windows XP is still the most commonly used version of its OS.

A few years ago Microsoft used a code name of Longhorn for the operating system which ultimately was released as “Vista.” Will Windows 7 have a real name upon release?

The real name of Windows 7 is: Windows 7. It’s not a temporary code name, like “Longhorn” was. The product will be officially called Windows 7 when it comes out on Oct. 22.

Is it possible to connect a netbook directly to a larger PC to transfer data? The data I am interested in would be Word documents, Excel files, a limited number of photos and music files, and other personal files.

While I haven’t tested it, I assume that, since a netbook is just a small, cheap, standard Windows laptop, you could use Microsoft’s built-in file-transfer utilities to accomplish this, provided you use the right cable. In Windows XP, the operating system on most netbooks and most other PCs in use, this is called the Files and Settings Transfer Wizard. In Vista, and the forthcoming Windows 7, it’s called Windows Easy Transfer.

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

I live in Puerto Vallarta, Mexico, for six winter months. I would love to have a Kindle. Can I download additional books in Mexico or must I download all I think I’ll want to read before I go?

Yes, you can, but it’s a bit of a convoluted process. Amazon says that, if you are a U.S. customer temporarily outside the U.S., where the Kindle’s wireless downloading capability won’t work, you can “sideload” books over the Kindle’s USB cable — normally used for transferring audiobooks or photos — from your PC or Mac.

According to Amazon, here’s how you do this. First, order a Kindle book on the Amazon Web site from your computer and tell it to send it wirelessly to your Kindle. This will fail. But you can then go to the “Manage Your Kindle” page on the Amazon site, which lists all the Kindle books you’ve bought under the heading “Your Orders.” Select the one you want, and click on the drop-down list at the far right labeled “Download/Send to…”. Select “computer” as your destination, and the book will be downloaded to your PC or Mac as a file with the suffix “azw.” From there, you can manually drag this file into your Kindle using the USB cable.

My husband wants to buy a laptop, but I said not to get one with Vista and to wait for Windows 7. Am I right?

I agree that, if he can do so, he should wait for Windows 7. While it isn’t officially released, my experience with its pre-release version has convinced me that Windows 7 is much faster, less annoying, and more compatible with third-party hardware than Vista is. You can read my first impressions of Windows 7 at: http://bit.ly/r9xEP.

• 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.

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.

Should I install Microsoft’s “SP3″ upgrade to Windows XP? I hear opinions on both sides.

In general, I recommend this upgrade, officially called Service Pack 3, because it beefs up security, and that helps not only you, but all Windows users, to avoid the spread of malicious software. If your PC is more secure, it is less likely to be used as a source from which other PCs can be infected.

I have upgraded a couple of XP PCs to SP3 without any downside. However, like you, I have also heard from some users that the upgrade caused them problems.

As with any major operating-system upgrade, either outcome can occur, depending upon your computer’s particular configuration and condition. So, if you’re on the fence, consider your level of concern about security.

How do cellular data cards compare with fast cable modems in terms of Internet speed? Are these cards more secure than Wi-Fi?

In my experience, using and testing cellular data cards on various laptops, they typically deliver, in real day-to-day use, somewhere between 300 kilobits per second and 1.5 megabits per second. By contrast, a fast cable Internet service can actually deliver up to 16 mbps. So cable is much faster.

Your security question is much more complicated. Wi-Fi security can range from very poor to quite good. It depends on where and how you use Wi-Fi, how you or others have set up the wireless network, and how you have configured your own computer.

Accessing the Internet over a cellular network is a more controlled process, because the cellphone-network operator manages the transmission, and in most cases supplies and configures the software on your computer. So, it is likely to be safer than the worst Wi-Fi setups. But I would never suggest that cellular data card transmissions are invulnerable to hackers or criminals.

What’s the difference between file-based backup and image-based backup software? Why would I choose one over the other?

Image-based backup software copies an image of your entire hard-disk, including all the programs, settings and obscure files that you never see. While it can be used to recover individual files, in some cases, it is mainly designed to allow you to restore your entire hard disk in the event that you lose it all.

File-based backup software, which is more common among consumers, is typically designed to preserve a copy of only your personal data, the material you can’t re-purchase or re-install if your hard disk dies.

That includes word-processing files, spreadsheets, presentations, emails, contacts, calendar items, photos and other items you created. It also is often used to back up music and video files that would be time-consuming, or very expensive, to re-acquire. And in some cases, it can preserve settings and preferences, such as Web bookmarks.

Both types of backup generally begin with a time-consuming initial session, followed by shorter sessions to update the backup with incremental changes.

Many people choose file-based backup because it occupies less space, and is generally quicker and also less expensive. Image-based backup is for folks who are willing to spend the added money and time to be sure they can restore their whole computer, or clone its contents completely to another machine.

• 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 bought an iPhone and was frustrated that my fingers appear to be too large to type properly on its virtual keyboard. Is there a stylus that works with the iPhone?

I hadn’t realized this until recently, when a friend who bought one showed it to me, but, yes, there is. The iPhone wasn’t designed to operate with a stylus, and the small, thin, hard kind that one uses with, say, a Treo, doesn’t work right with the iPhone. But there are some companies that sell a wider type of stylus with a soft tip that approximates a small fingertip, and is designed for the iPhone.

If you type “iPhone stylus” into a search engine, or an online store like Amazon.com, you will see a number of inexpensive choices. One downside: the iPhone doesn’t have a built-in slot for a stylus. My friend carries his, which has a clip on the end, like a pen, in his pocket.

I just purchased an external hard drive for my PC that connects through a USB port to back up photos and important files in the event of a computer crash. Would this hard drive be affected if my main hard drive crashed? Should I disconnect the external drive when it’s not in use?

The two hard disks are separate devices, and if one has a mechanical failure, it doesn’t affect the other. There might be some scenarios in which a problem with the computer itself, as opposed to a breakdown of its internal hard disk, could affect the external drive. And malicious software could corrupt or erase files on the external drive. An electrical surge could also affect both drives, or fry the computer itself.

Many people can’t disconnect their external drives, because they use automated backup programs, or frequently save files to the drives. If you are doing only occasional manual backups, you could disconnect the extra drive when not in use, so you’d feel more comfortable. But, for maximum peace of mind in case of an electrical surge, you should disconnect it not only from the PC, but from the electrical outlet as well, even if you are using a surge protector.

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