With the new iPods coming out, how do you deactivate an old one? I think Apple only allows a certain number to be used with an account.

You don’t have to deactivate an iPod if you replace it. The copy-protection rules imposed on Apple by the entertainment companies allow for copy-protected music and videos purchased from the iTunes Music Store to be stored and played on an unlimited number of iPods.

The only “deactivation” iTunes users have to perform is on a computer — Windows or Mac — because the copy-protection rules allow purchased, copy-protected songs and videos to be played on no more than five computers at a time. So, before you replace a computer on which you are storing such purchased, protected iTunes material, you should deauthorize the machine by going to the “Store” menu in iTunes and selecting “Deauthorize Computer…”.

Of course, if you aren’t at or near the five-computer limit, this issue may not matter. It’s also irrelevant if none of the music or videos you play from within iTunes is copy-protected material purchased from the iTunes store. You can happily use iTunes and iPods without buying any copy-protected stuff from Apple. You can restrict your music and videos to those you copy from legally obtained CDs, those you create yourself, or those you buy in unprotected formats from iTunes, or other sites, like eMusic.

I have a printer hard-wired to a desktop computer, but would like it to be available to my laptop wirelessly over my home network. How can I do this?

There are two main methods, assuming the printer doesn’t have a built-in networking port or Wi-Fi transmitter. One method is to buy a small box called a print server and plug it into your router. Then, you plug the printer into the print server, and, with the right software and settings, it will appear on your network and be available to any computer on the network, wired or wireless.

The same companies that make routers, such as Linksys and Belkin, also often make these print servers. The other method is to buy a wireless router that has such a print-server function built-in, with a USB port for connecting a printer.

If I have a laptop with Wi-Fi capability, does that mean I can surf the Web while sitting in a car?

Yes, but only if the car is in range of a Wi-Fi network that is either open (not password-protected) or for which you know the password. And it would only be practical if the car was stopped or parked, since a car moving at normal speed would very quickly drive out of range of any networks you encountered.

A better option, which works even when a car is moving, is to purchase a high-speed cellular wireless modem for your laptop, or buy a laptop with such a modem built-in. These modems, which get you on the Internet via citywide cellular-data networks instead of Wi-Fi, can remain in range for miles. But they require hefty fees, typically $60 a month. And, of course, you should only be surfing the net in a moving car if you are a passenger in that car, not the driver.

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 securing a wireless network, adapters that play the music stored on a PC through a stereo and voice-recognition software.

Last week you advised readers that, in order to stop people from piggybacking on a wireless network using a Linksys router, they should simply set up a password and keep it private. But don’t they need to enable an “encryption key?”

Yes. Most nontechnical folks would consider an encryption key as a kind of password, and that’s the word I used because I always try to write my columns in plain, conversational English. In this case, however, my use of the term may have caused confusion, because there are, in effect, two kinds of passwords on Linksys routers and most other brands of routers. One just prevents strangers from changing the router’s settings. The other — the one to which I was referring — is required to actually access the wireless network. That’s the one that’s technically called a “key.”

To enable the encryption key, use the router’s setup software to turn on security. On newer models, the strongest security system is called WPA, and on older models, it’s called WEP. Once it’s enabled, only people who know the key can get onto your network. There are further steps you can take, like hiding your network’s name (called an SSID) from others, or even restricting access to the network to specific computers with specific identification codes (called MAC addresses, a term that has nothing to do with Apple’s brand of computers.)

For more details, go to Linksys.com, select “Learning Center” at the top of the page, and click on “Network Security” from the menu that appears. And then click on the link called “How to Secure Your Network.”

Is there a stereo that I can buy that can wirelessly connect to my computer and play the same music I play with Apple’s iTunes on that computer?

Yes. If you literally mean a stereo, rather than an adapter for a stereo, the best I know of is called Sonos ZonePlayer 100. It involves a module you connect to your computer that links wirelessly to stereo units with built-in amps in remote rooms of your house. It has a beautiful remote control with a color screen and many other great features.

But it’s expensive — about $1,200 for the starter package, without speakers — and can’t play copy-protected music you buy from iTunes, only music you import from your CDs or other unprotected files. Information is at sonos.com. For much less money, you can also buy adapters that can play the music on a PC, or an iPod, through an existing stereo.

I have been keeping a journal or diary. It is hand written but I would like to make the journal more readable by others. Is there voice-recognition software that you would recommend, so I can dictate the entries?

It has been years since I reviewed voice-recognition software, but Dragon Naturally Speaking, a Windows program, works well. For more information, see nuance.com. And Microsoft’s new Vista operating system has a decent built-in voice recognition system. If you are using a Macintosh, one widely known speech-recognition program is called iListen, but I haven’t tested it. Information is at macspeech.com.

* * *

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 questions about using Quicken in Vista, blocking people from piggybacking on your wireless router signal and waiting for Mac’s Leopard operating system.

We waited to purchase our new computer until Windows Vista was released. We now have a new HP Pavilion 9000 and were trudging along the learning curve when we came to a complete halt — there is no version of Quicken available for Vista. Since we use Quicken extensively, we are stuck using our old computer. When can we expect to be able to use Quicken on Vista?

I haven’t tested Quicken in Vista, but Quicken’s maker says it works fine in Vista, though you may have to download and install a free update. According to Intuit, the manufacturer, “Quicken 2007 has been tested with Microsoft Windows Vista, and no known issues exist in the most current release.” The current release of Quicken 2007 is called “Release 4 (R4).” If your release is R3 or below, you will have to download and install a patch. You can find more information by going to quicken.custhelp.com and typing “Vista” into the search box.

I use a Linksys Wi-Fi router in my home. How can I make sure that no one else is piggybacking on my signal?

It’s pretty simple. Turn on the password feature in your router, and don’t tell anyone the password. You’ll usually find the password setting in the installation software that came with the router.

I’m thinking of buying a new iMac, but should I wait until Apple releases its new Leopard operating system? When will that be?

Apple is saying that Leopard, the coming version of its Mac OS X operating system, will be released this spring. Based on past experience, any Mac you buy now should be able to run Leopard fine. In recent years, Apple’s operating-system upgrades have been much smoother than Microsoft’s. So, if you really need the new Mac now, I wouldn’t worry about Leopard.

However, if you can wait a few months, and buy your iMac with Leopard preinstalled, I suggest doing so. For one thing, you’ll save some money, since Apple usually charges $129 for new operating systems. For another, it’s possible that Apple will also improve the iMac hardware, though I stress that I know of no such plan.

* * *

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

But there’s more than one way to get a strong, fast Internet signal all over your house. You aren’t limited to using a single wireless router. You don’t have to install a bunch of complicated wireless “range extenders.” And you don’t have to snake networking cables through your walls.

Instead, there’s a simple alternative that’s often overlooked: Using small gadgets called Powerline adapters, you can route your Internet connection around your house over your regular electrical power lines, the ones already in your walls. It really works, it’s fast and it doesn’t disrupt your electrical system. Even better, it requires zero technical skill.

You just plug one of the adapters into a standard electrical outlet near the place where your Internet connection enters your home. Then, you connect the adapter to your wired or wireless router. Next, you plug a second, identical adapter into an electrical outlet in a distant room where you lack an Internet connection. Finally, you plug a computer (or even a wireless access point) into that second adapter. There’s no setup, no required software and no technicians or tools are needed.

When you plug in a computer into the second Powerline adapter, it’s as if that computer was right next to your cable or DSL modem and router. You are on the Internet at full speed. If you plug a Wi-Fi wireless access point into the second Powerline adapter, it will create a wireless network in and around the distant room, which multiple computers can use.

I first reviewed these Powerline adapters in 2003. I liked them, but they were a little slow and never took off. Now, however, one of the leading home network product makers, Netgear, offers a whole line of faster Powerline adapters.

I’ve been testing one of Netgear’s newest models, the XE104, which costs $100 per adapter, and I can heartily recommend it. It couldn’t be simpler or more effective. In my tests, the XE104 gave me wicked-fast connections. I tried plugging Windows and Macintosh laptops directly into the adapters in rooms where my wireless signal was weakest. I also tried plugging a Wi-Fi wireless access point into an XE104 adapter and picking up the connection wirelessly on the laptops. (An access point is a wireless gadget that takes a wired Internet connection and propagates it through the air.)

In all scenarios, the Netgear XE104 adapters delivered nearly the full speed of my Internet service, which in my case is very fast — 15 megabits per second downstream and two mbps upstream. In fact, the XE104 can handle speeds up to 85 mbps, far faster than any common connection.

You can use up to four Netgear adapters at once, and the company claims they will cover a 5,000-square-foot home. Netgear includes optional software to encrypt your Powerline connection, but this is needed only if you share an electrical system with other families.

Linksys, Belkin and other companies also make Powerline adapters, sometimes called bridges. But Netgear is the leader in this category, and I didn’t test the other brands.

The XE104 is a small, white rectangular gadget about 4 inches high, 3 inches wide and 1.5 inches thick. It carries a standard two-pronged electrical plug and mounts right into the wall outlet.

On the side, there are four standard Ethernet network ports, like the kind on your router and laptop. Netgear includes a short Ethernet cable so you can connect the first adapter to your router and the second one to a PC or a wireless access point.

The four Ethernet ports are what make the XE104 a “switch.” They allow you to connect each adapter to multiple devices. For instance, the first adapter can be connected both to your router and to a PC. The second might be connected to a PC, a wireless access point and a device like a game console.

Netgear makes a similar model without the multiple Ethernet ports, called the XE103, for $80. There’s also a costlier model that goes up to 200 mbps, though that’s overkill for 99% of people.

The company also makes a Powerline adapter with a built-in wireless access point for the distant room, the $150 WGXB102 model. This saves you the cost and hassle of buying and connecting a separate access point. But it’s slower and uses older technology. In my tests, it was less than half as fast as using the XE104 with a separate, modern wireless access point.

Unfortunately, like a lot of network-equipment makers, Netgear is clueless about naming products so that normal humans can understand what they are. The XE104 is officially called the XE104 85 Mbps Wall-Plugged Ethernet Switch. That’s like calling a table lamp the LS482 75 Watt Wall-Plugged Switched Illumination Device.

Netgear even makes it hard to find the XE104 on its Web site, netgear.com. It lists it under a section called “Bridges, Access Points, and Range Extenders.” You can buy them at computer stores and other retail outlets.

These adapters are a terrific way to clear up Internet dead spots.

• Email me at mossberg@wsj.com.

Lots of new technologies claim to be transformative, productivity-enhancing and liberating. But only a few really live up to those claims. One of them is Wi-Fi, the wireless networking technology that has truly revolutionized the way people use the Internet.

With Wi-Fi, you can get online in any room of a home or office — not just the room where your wired Internet connection lives. And you can use the Internet in airports, coffee shops, hotel lobbies and lots of other places where it wasn’t possible before.

But like a lot of technologies, Wi-Fi has been changing so fast that confusion has crept in. A new version of Wi-Fi, generally known as draft-N, promises greater speed, greater range and standardization, but may not deliver any of those things. I’ve been testing some of this latest Wi-Fi gear, with mixed results.

Linksys draft-N router

Also like some other technologies, Wi-Fi adheres to standards set by a private engineering organization called the IEEE (Institute of Electrical and Electronics Engineers), in which representatives of interested companies participate.

The current version of Wi-Fi blessed by the IEEE is called G and has a maximum speed of 54 megabits per second. This G version of Wi-Fi, known to techies as 802.11g, is built into most wireless routers (which transmit and receive Wi-Fi signals) and most laptops.

Now, the IEEE is working on a new, faster standard called N. It promises much greater speeds, measured in the hundreds of megabits per second, and much better range. But certifying this N standard is taking forever, partly because of factionalism within the IEEE.

In the meantime, the marketplace has moved on. Last year, major makers of Wi-Fi routers, like Linksys and Belkin, brought out routers that used a major advance, called MIMO, expected to be in the eventual N standard. This technology uses multiple antennas to send and combine multiple data streams into one faster, longer-range signal.

Last year, I endorsed one of these MIMO products, Belkin’s Pre-N router, which was the only Wi-Fi router I ever tested that covered every corner of my home at decent speeds, even when I used laptops with only the older G technology built in.

Now, the Wi-Fi market has moved again. The major makers have all brought out what they call draft-N routers and cards for laptops that adhere to a draft of the coming N standard that the IEEE has passed. It’s probable, but not certain, that the final N standard likely to emerge next year will comply with this draft. Similar draft-N gear will be built into new laptops later this year.

The makers are claiming that the draft-N routers will have up to 12 times the speed and four times the range of G equipment when used with compatible laptop cards. Even if you are just using a laptop with a G receiver built in, the new routers can also improve speed and range, though more modestly.

Speed is nice, but even current G maximum speeds far exceed the speed of most home DSL or cable modem connections. What’s more important to most consumers is range, or more accurately, decent speed at longer ranges. The biggest Wi-Fi problem people face is dead spots or very slow connections in parts of their homes.

I tested the new Belkin draft-N router, called the Belkin N1, in my house and compared it with the Belkin Pre-N router I bought last year and have used ever since. The new router, which I placed in exactly the same spot as the old one, was easy to set up. It has lovely, large icons on the front that tell you if everything on your network is connected and working.

But the N1 didn’t perform any better, and in some cases did worse, than the old Belkin. This was true whether I was testing it on a Windows laptop or a Mac laptop, and whether I was using the Belkin N1 laptop card or just the built-in G radios in my test laptops. The new model covered my whole house, but so did the old one.

I also tried the Linksys draft-N router, called the WRT300N, which has an antenna array that makes it look like a radar station or a submarine conning tower. The company had to help me set it up, because I use a very fast Internet service called Verizon FIOS, which the router’s program doesn’t recognize. The Linksys proved much slower than the Belkin, though this may be because of a mismatch between its settings and my Verizon service, which is used by only a few hundred thousand homes in the U.S.

My unimpressive draft-N experience is confirmed by several, more extensive tests done by some magazines and Web sites, which showed the draft-N gear to be no big deal.

There are two other problems with the draft-N systems. The manufacturers aren’t promising to upgrade them to the final N standard when it emerges. And buying them will get more complicated in the coming months, because they will be offered in a range of speeds and even in two different frequencies.

I can’t recommend the draft-N equipment over the previous round of MIMO-equipped routers. They will likely be better than your G equipment, but so were last year’s models.

• Email me at mossberg@wsj.com.

Corrections & Amplifications:

A new, faster standard for Wi-Fi wireless network connections promises speeds measured in the hundreds of megabits per second. This column incorrectly says the new speeds would be in the hundreds of megabytes per second.

Now, there’s an even better approach to running Windows on a Mac. It’s called Parallels Desktop for Mac, and it’s from a small Herndon, Va., company called Parallels. It emerges from testing today and goes on sale for $79 at the company’s Web site, parallels.com.

I’ve been testing Parallels Desktop on a new MacBook Pro laptop, and have found it works very well, despite a few drawbacks. I prefer it to Apple’s solution, even though the Apple approach is free and also works very well.

Apple’s system, called Boot Camp, has one big limitation: It allows you to run only one of the two operating systems at a time, requiring you to reboot the computer to switch between them. As a result, you can’t quickly jump between Mac programs and Windows programs. You can’t, for instance, simultaneously download your corporate email in Outlook using Windows while editing a home video in iMovie using the Mac OS.

With Parallels Desktop for Mac, you can do this. You can run any combination of Mac and Windows programs at the same time, on the same screen. No rebooting is necessary. You can even cut and paste material between Mac and Windows programs, and share files between the two environments.

The Parallels approach, called virtualization, runs Windows, with all its features, inside a window in the Mac operating system. It creates a faux Windows PC, called a “virtual machine,” that co-exists with Mac OS X. You can devote the full screen to either operating system or you can reduce Windows, and whatever programs it’s running, to a window on the Mac that can be dragged anywhere on the screen and made as small or as large as you like.

Unlike Boot Camp, Parallels Desktop can run every version of Windows back to Windows 3.1, not just Windows XP. It can also run Linux and even older operating systems like OS/2 and MS-DOS. You can even create and run multiple virtual machines, with different operating systems inside, up to the limit of your Mac’s memory.

Virtualization isn’t a new concept, and it’s not even new on the Mac. Microsoft offers a product called Virtual PC for Mac that runs Windows inside a window on older, pre-Intel Macs. But Virtual PC runs painfully slowly on these older Macs, and it can’t run every Windows program. It doesn’t run at all on the new Intel-based Macs.

Parallels Desktop runs Windows a little more slowly than Apple’s Boot Camp does because it is accessing the Mac’s hardware through the Mac operating system rather than directly, as in a dual-boot system. But, in my tests, it was very snappy, as fast as many regular Windows computers.

Inside my virtual Windows machine, I was able to run programs like the Windows version of Microsoft Office, the Windows versions of the Firefox Web browser, iTunes, Adobe Reader, Google Earth and more. All worked well, as did Microsoft’s Internet Explorer Web browser, Google’s Picasa photo program and Google’s Google Talk instant-messaging software.

I was able to do email in Apple’s Mail program while simultaneously watching a baseball game in Internet Explorer inside my Parallels Desktop Windows virtual machine. I wrote part of this column in the Windows version of Microsoft Word and part in the Mac version, cutting and pasting between the two.

And, unlike Boot Camp, Parallels Desktop doesn’t require you to dedicate a fixed section, or “partition,” of your hard disk to Windows. Its virtual Windows computer is contained in a big Mac data file that uses only as much space as Windows needs.

Setting up Parallels Desktop is fast and easy, though some novice users may find the program’s terminology a little daunting. As with Boot Camp, you have to supply your own copy of Windows to install once you create the virtual machine. And because the virtual Windows machine created by Parallels behaves like a real Windows computer, you have to install the usual raft of Windows security software.

So what are the drawbacks? I couldn’t eject a CD in Parallels without switching back to the Mac environment. Parallels treats fast USB 2.0 ports on the Mac as if they were slower USB 1.1 ports. It doesn’t support Microsoft’s DirectX technology, which many games rely on. The company pledges to fix these things in future versions.

Also, if you elect to use the optional file-sharing feature, your Mac data files could be corrupted or erased by a Windows virus. For that reason, this feature is turned off by default.

Still, Parallels Desktop is a very good product and a pleasure to use. It’s like having two computers in one, the best of both worlds.

• Email me at mossberg@wsj.com.

Still, for all its success, Skype has been a niche product, little used by mainstream, non-techie consumers. Much less popular in the U.S. than in Europe, it has mainly appealed here to budget-conscious folks like students and recent immigrants, who often want to make lots of international phone calls.

There are two big reasons for Skype’s niche status. First, many computers aren’t equipped with microphones. Most modern laptops come with built-in mikes, but the vast majority of PCs are still desktops, which typically lack mikes. Second, even when computers have mikes, they make clumsy telephones when compared with real phones, which are specifically designed for voice communication.

In addition, free Skype calls can be made only to other Skype users. If you want to call nonmembers who use real phones, you have to sign up for a prepaid service called SkypeOut, although, at two cents a minute, the calls are cheap.

Now, however, Skype is putting those hurdles behind it. Today, the company plans to release a major new version of its phone-calling software, Skype 2.0, with added features — including video calling — and a cleaner interface. It is taking steps to make computer microphones cheap and easy to obtain. More importantly, it is moving its service off the computer to a new breed of Internet-based telephone handsets.

I’ve been testing Skype 2.0, along with the new, cheap, Skype-branded microphones and a new Skype-compatible phone that frees users from sitting in front of a computer while talking. Despite some flaws, this new combination of hardware and software generally worked well, and I believe it stands a chance of propelling Skype into the mainstream.

There’s nothing new about using a computer as a phone. And free computer-to-computer phone calls, among fellow users of a service, are also common now. America Online, Yahoo, Microsoft, Apple Computer, Google and others have offered this service for a while. Most also already offer free video calls — something Skype is just now adding — for users with Web cameras.

But Skype is the company most identified with free Internet phone calls, and it is trying hard to keep that status. The new Skype 2.0, available at Skype.com, is ready now for Windows and will soon be released for the Macintosh and other platforms.

In my tests of Skype 2.0, I used two different Windows computers to place voice calls to Skype users in California, New York and Berlin, Germany. I also made a couple of SkypeOut calls to phones in the Washington, D.C., area.

The new Skype software was easy to use. It searches for people you know to see if they are registered members, and it lets you add them to your contact list with one click.

All my test calls were very clear, though in most cases there was a slight problem in the first few seconds, when callers couldn’t hear me. In a couple of cases, the sound dropped out briefly during a call. And Skype disconnected my call to Berlin in the middle, forcing me to redial. Still, as a tradeoff for free calls, the glitches were tolerable.

I used a variety of microphones, built-in and added-on, cheap and expensive. In general, the built-in and costlier add-on mikes worked best. Skype’s new cheap mike, which comes with an earbud as part of a $4.99 Skype “starter pack” available at RadioShack stores, was a little muffled unless I held it close to my mouth.

I also made a few video calls, using a Logitech Web camera. These worked fine, though they displayed the graininess that marks most Web video calling. An audio conference call also worked well, though you can’t use video if you’re calling more than one person. Skype also offers a conventional text-based chat system and a feature for transferring files. I tested both, and they worked fine.

But I was most impressed with the new Skype phone I tested, the $100 Linksys CIT200. It looks and works like a regular cordless phone. But it links wirelessly to a little base station that connects to your computer. And it has a big Skype button that connects you to the Skype service via the PC. The phone displays your Skype contacts, and you call them with the press of a button. You can also make calls to non-Skype phones, via SkypeOut.

I tested the phone by calling both Skype users and non-Skype users, and it worked great everywhere in and around my home — upstairs, downstairs, even outside in the yard.

There are other phones that can now use Skype, ranging from a $16 handset that connects to the PC with a cable to a $100 cellphone-style wireless headset and a $140 cordless phone that can use both Skype and your regular phone service to place calls. All of them liberate Skype users from the PC.

Skype has escaped from its niche and is heading for the mainstream. You might want to give it a try.

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