As always, this is a general guide aimed at mainstream, nontechnical consumers who dwell on common tasks such as email, instant messaging and surfing the Web; managing and lightly editing photos, videos and music; and using basic office applications. It is not intended for heavy gamers, video producers or corporate buyers.

There’s a vast variety of laptop models, but this guide is meant to cover the most common types of laptops, those with screens from about 12 inches to 17 inches, and weights ranging from around 2.5 pounds to 7 pounds.

For this column, I’m not including the category of tiny machines now called netbooks, with screens under 10 inches. I am also ignoring the huge, heavy laptops with screens larger than 17 inches that are primarily aimed at gamers.

Even the remaining mainstream machines range wildly in price, from bargain-basement models at $350 to high-end ones that can top $3,000. In my experience, the top brands for technology and reliability are Apple and Lenovo’s ThinkPad line, but various models from Sony, Hewlett-Packard, Toshiba and Dell are also worth investigating.

So, here is a quick guide to the key factors you should consider when buying a laptop.

Size: If you are a constant traveler, think about the subnotebook models, which generally weigh 3 pounds or less. There are two types of these. The classic subnotebook has a small screen, 12 inches or less, and a cramped keyboard. This year, a new type emerged, with a full keyboard and a normal 13.3-inch screen packed into a thin, light body. There are two of these: the MacBook Air from Apple and the Lenovo ThinkPad X300. All subnotebooks are relatively costly, typically ranging from $1,500 to over $3,000.

If your laptop will mostly stay at home, the office, or in class, a 5-7 pound machine with a screen of either 13.3 inches or 15.4 inches is the best bet. A well-equipped model in this class is likely to run you between $800 and $1,200. Typical models in this class are the Dell Inspiron 1525, the HP dv6700 and the Apple MacBook.

Windows vs. Mac: This is the eternal question. In my view, Apple’s Leopard operating system is faster, better and far less prone to malicious software than Microsoft’s Vista operating system. And the Mac laptops also come with better built-in software. The $1,099 MacBook is a solid, fairly priced machine, and the $1,999 MacBook Pro is even better. Both also can run Windows.

But Windows laptops are often less expensive, tend to have a greater variety of ports and slots, and come in more styles and sizes.

Apple’s MacBook

Operating system: If you are buying a Windows laptop, be aware that Vista is slower than Windows XP, in my experience, and still has compatibility issues with add-on hardware and software. If you’d prefer to stick with XP, you will find that many fewer models are available with it. And Microsoft has decreed that after June 30, mainstream, name-brand laptops will no longer come pre-equipped with XP.

Video: I recommend getting an LED-powered screen, which is brighter and saves power. Also, if you are choosing Vista, or if you do a lot of converting video for use on portable devices, consider getting a laptop with a separate video card inside that has its own memory.

Memory: If you’re buying an Apple laptop, two gigabytes of memory is plenty. If you’re using Vista Home Premium, I’d consider three gigabytes for best performance.

Processor: Any dual-core processor will be fine. Don’t pay a penny extra for faster processor speed.

Storage: In a mainstream laptop that will be your main computer, look for a 160-gigabyte hard disk or larger. A new kind of storage, called SSD, or solid state disk, is now available. But it is still way too costly for most users, and at the moment is available only in smaller capacities.

Battery life: Many laptops today rarely spend time away from an electrical outlet. But if yours will, look for a battery life of at least three hours between charges.

Wireless: Make sure your new laptop has the new, faster “N” version of Wi-Fi built in. Many cheaper laptops don’t. You can also get a cellphone modem built in, but they are costly and carry a monthly fee. You can always add an external cellphone modem later.

Other features: A built-in camera and microphone can be quite useful, and so can a feature on some Windows machines that allows you to play music and videos without fully booting up the computer.

Don’t let yourself be swayed by sales pitches, or by fanaticism for or against Windows or the Mac. Think hard about how you use your computer and what your budget will allow, and stick to those priorities.

• Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.

Hard-disk drives, or HDDs, are mechanical devices. They work by recording data on a spinning magnetic platter or platters. By contrast, solid-state drives are made of chips and have no moving parts. They are close cousins to the so-called flash memory used in digital cameras, cellphones and smaller-capacity music players. They record data to special memory chips that retain their contents even when the device is turned off.

Solid-state drives have some key advantages. Because they lack moving parts, they are faster, draw less power, are harder to damage and are quieter than hard drives. Unfortunately, today’s early versions of SSDs for laptops also have two big drawbacks when compared with hard drives: They offer much lower capacity and have much higher prices.

For instance, on the newly announced Apple MacBook Air ultrathin laptop, the HDD version costs $1,799 and stores 80 gigabytes. The SSD version costs $2,798, but actually stores less — just 64 gigabytes. On the Toshiba Portege R500 subnotebook, the basic hard-drive version costs $1,999 and stores 120 gigabytes. The cheapest SSD version is $2,699 and also stores just 64 gigabytes.

Despite these limitations, I believe SSDs are likely to become more common and more popular as their capacities increase and their prices drop. Samsung, which makes the 64-gigabyte SSDs in both the Apple and the Toshiba, has already announced an SSD with twice the capacity that costs much less per gigabyte of storage.

I’ve been testing the SSD models of the Portege R500 and the MacBook Air to see how they measure up to their HDD counterparts. My verdict is that the SSD does deliver on its promises, but, in some cases, just barely.

For the small slice of users who are deeply and constantly worried about hard-disk failures, it may be worth it to pay a huge premium today for an SSD that stores less. Because SSDs aren’t subject to mechanical failures, your data are probably safer on them. But for mainstream users, my conclusion is that it’s too early to take the plunge on SSDs, and the best strategy is to wait for prices to drop sharply and for capacity to rise.

In my tests, I focused solely on comparing the hard-drive and SSD models of each machine, which I had had already reviewed in earlier columns. On the same computer, I wondered, would the SSD make a significant difference in speed and in battery life?

To measure battery life, I conducted my usual harsh test, where I turn off all power-saving software, set screen brightness to maximum, turn on the Wi-Fi and play an endless loop of music.

In this test, the SSD made little difference in the MacBook Air and, in fairness, Apple is making no claims of any significant battery-life gains on its SSD model. The SSD MacBook gave me just five more minutes of battery life. Apple says this is because its hard-drive model already uses a very low-power drive.

On the Portege R500, my first battery test with the SSD model actually yielded significantly less battery life than the hard-drive model. The reason: Toshiba ships the base SSD model with a battery with only half of the capacity of the hard-drive model.

When I swapped in the normal battery, which costs $117 extra, the SSD model gave me an added 1 hour and 21 minutes of battery life, about a 36% increase. That extra battery life likely would translate to nearly 2½ hours in more normal usage. It may be worth the huge price premium for some folks.

On both computers, the SSD was faster than the HDD models. The SSD version of the Apple booted up from a cold start, and rebooted with several programs running, about 40% faster. But the gain isn’t as impressive as it seems because even the hard-drive versions of the MacBook Air booted up in under a minute and rebooted in just a little over a minute.

On the Toshiba, which was running Windows XP, the SSD model knocked about 40 seconds off a cold boot time on the HDD version of 2 minutes and 7 seconds. On my reboot test, starting with several programs running, the SSD model was 80 seconds faster. I imagine that on laptops with the slow-booting Windows Vista, the improvements might be more meaningful.

I also tested launching Microsoft Word and Excel, and opening a couple of hefty PDF files on both machines. The SSD versions were faster. But in most cases, the gains were just a few seconds or even fractions of a second.

All in all, the SSD is a promising improvement over the hard drive, but now is not the time for most users to buy it.

Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.

I’ve been testing two of the latest efforts to crack that problem. The first is from Toshiba, a company that once dominated the laptop world, but has since slipped badly. The other is from Dell, best known for larger, clunkier laptops. Both machines are stylish and worked fine in the tests, but each has flaws that might give a buyer pause.

These two new laptops, which use Intel’s Core 2 Duo processor, are very different in size. The Toshiba Portege R500 weighs just 2.4 pounds, has the footprint of a standard sheet of paper and is only about ¾-inch thick at its thinnest point. Yet it squeezes in a DVD drive. It sports a 12.1-inch widescreen display with very good resolution. The screen is lit by LEDs instead of by traditional lamps. That makes for more brightness and saves power.

The Dell XPS M1330, while still relatively small, is larger than the Toshiba. It weighs a hair under four pounds, has a larger footprint and is thicker. It falls into a hot new laptop category that features 13.3-inch widescreen displays — a size considered a good compromise between the small displays on the lightest laptops and the larger ones on the heavier models. The M1330 has some very un-Dell-like aspects to it, such as a choice of three lid colors and a slot-loading DVD drive that doesn’t require a pop-out tray.

Toshiba claims the R500 is the world’s thinnest notebook with a built-in DVD or CD drive. Dell claims the optional LED version of the M1330 is the thinnest with a 13.3-inch screen.

The Toshiba starts at $1,999 for a unit with a 120 gigabyte hard disk, a gigabyte of memory, and built-in Wi-Fi and Bluetooth wireless networking. The Dell starts at $1,299 for a model with a 120 gigabyte hard disk, a gigabyte of memory, built-in Wi-Fi (but not Bluetooth) and standard display. An LED display costs $150 more; Bluetooth is an extra $20.

I tested the base model of the Toshiba R500 and found that it performed well. My particular machine came with Windows XP, though Windows Vista is also available in a model that costs $150 more. The tiny silver computer handled everything I threw at it, including Microsoft Office, the Firefox Web browser, the iTunes music program and more.

Toshiba’s Portege R500, top, and Dell’s XPS M1330

In my tough battery test, where I turn off power-saving features, maximize screen brightness, turn on Wi-Fi and play an endless loop of music, the R500 lasted an impressive three hours, 44 minutes. I estimate that in more normal use, you could get five hours of battery life.

But my test Toshiba, a production unit, had a major flaw: The DVD drive didn’t work. Apparently, the lens on the drive had come loose in shipping. Toshiba sent another unit with a working drive, but this is a major issue because the machine uses a new, very thin type of DVD drive that seemed fragile to me.

In fact, the R500 lacked a solid feeling overall. The keyboard was OK, but the touch-pad buttons seemed flimsy and stiff, and I had the impression that this was a computer you’d have to treat gently. It also had trouble reconnecting with my Wi-Fi network after waking up from its sleep state. And it was loaded with the trial software and offers I call craplets.

The Dell XPS M1330, on the other hand, felt solid through and through. From its crimson cover to its wedge shape, it’s also a handsome laptop. The unit I tested had the LED screen and a full complement of options, which would have brought its price to $2,188.

Like the Toshiba, the Dell speedily handled Microsoft Office, Firefox, iTunes and other software. Its Wi-Fi worked very well. My test model used Vista, and had the extra memory and souped-up graphics Vista needs to work well. The M1330 isn’t available with Windows XP. To Dell’s credit, it can be ordered with no craplets on it, for no extra money. But because it uses Vista, it starts up painfully slowly. A reboot took more than four minutes.

The big flaw on the Dell is battery life, a major downside for a machine meant to travel. In my test, the M1330 lasted just two hours, 27 minutes; so, you’d be lucky to get 3.5 hours out of it in normal use. Dell says the base model would do better because it has a wimpier, but less power-draining graphics system. You can get a bigger battery for $30 more, but it makes the machine larger and heavier.

The Dell XPS M1330 is a good, solid, mobile computer that needs better battery life and can get expensive once you start ordering options. The Toshiba R500 seems like a dream machine for travelers, but its DVD defect is worrisome and you may have to treat it like glassware.

• Email me at mossberg@wsj.com. Find all my columns and videos online free at the new All Things Digital Web site, http://walt.allthingsd.com.

This isn’t Microsoft’s first effort to stop the iPod, but it’s the first for which the software giant is adopting Apple’s own business and design model — where one company makes and controls the hardware, software and online component, and tightly integrates them. The Zune is produced by Microsoft’s Xbox group, which builds game consoles on that same end-to-end principle.

Microsoft’s Zune comes in black, white or brown.

In its first incarnation, the Zune comes in only one version, a big, chunky $249 model that can hold 30 gigabytes of music, videos and photos. I’ve been testing the Zune for the past couple of weeks and comparing it with the most similar of Apple’s six iPod models — the smaller of the two full-size iPods, which also holds 30 gigabytes and also costs $249.

Zune has several nice features the iPod lacks: a larger screen, the ability to exchange songs with other Zunes wirelessly and a built-in FM radio. It solves the worst problem that plagued earlier Microsoft-based music players — frequent failures to synchronize properly music and videos between the players and personal computers. Synchronization on the Zune is smooth and sure.

Also, the Zune player and software have a very good user interface, different from, but in some cases easier to use than, the iPod’s. While it lacks the famous iPod scroll wheel, instead using a common four-way navigation pad, I found song lists easy to navigate on the Zune. It has only a few buttons and is quite intuitive to use. To my ears, it sounded as good as the iPod.

But, this first Zune has too many compromises and missing features to be as good a choice as the iPod for most users. The hardware feels rushed and incomplete. It is 60% larger and 17% heavier than the comparable iPod. It has much worse battery life for music than the iPod or than Microsoft claims — at least two hours less than the iPod’s, in my tests. Despite the larger screen, many album covers look worse than they do on the iPod. And you can’t share music libraries between computers like you can with iTunes.

Zune’s online store offers far fewer songs, just over two million, compared with 3.5 million for the iTunes store. In fact, as of this writing, songs from one of the big labels, Universal, were missing from Zune Marketplace, though Microsoft says it is confident it will have all the major labels when it launches Zune on Tuesday. Also, despite the player’s capability, Zune Marketplace offers none of the TV shows, movies or music videos that iTunes does, and has no audiobooks or podcasts.

Even worse, to buy even a single 99-cent song from the Zune store, you have to purchase blocks of “points” from Microsoft, in increments of at least $5. You can’t just click and have the 99 cents deducted from a credit card, as you can with iTunes. You must first add points to your account, then buy songs with these points. So, even if you are buying only one song, you have to allow Microsoft, one of the world’s richest companies, to hold on to at least $4.01 of your money until you buy another. And the point system is deceptive. Songs are priced at 79 points, which some people might think means 79 cents. But 79 points actually cost 99 cents.

Unlike iTunes, Zune offers subscription plans, where you can get an unlimited numbers of songs for $15 a month. However, Microsoft is de-emphasizing this option and mostly positioning Zune Marketplace as a source of individually purchased songs and albums.

Some consumers may well choose Zune for its big screen, which looks great with photos and videos, for its wireless song swapping, or for its FM-radio capability, which requires a $50 accessory on the iPod. Others may favor Zune because they are as tired of Apple’s dominance in music as some folks are of Microsoft’s dominance in computers.

But Zune has only around 100 accessories at launch, versus 3,000 or more for the iPod. If you have any iPod-specific accessories, they won’t work on the Zune. Also, none of the songs you may have purchased from Apple will play on the Zune, unless you undertake a laborious conversion process. Apple is rumored to be working on an all-new iPod with a screen as large or larger than the Zune’s.

Zune marks an unusual turn for Microsoft. The company is abandoning its favored business model, where it builds software platforms and then lets other companies make a wide variety of products that use that platform. Instead, Microsoft is building and totally controlling the whole chain associated with the product: the hardware, the software and the online music store. Songs sold on Zune Marketplace are intended to play only on the Zune, and Zune players won’t be able to play copy-protected songs bought elsewhere, even at other online stores that use Microsoft music formats.

Microsoft was driven to this approach because its platform model, so successful with personal computers, has failed miserably in the music category. Apple has simply rolled over all the hardware companies and online stores that were built around Microsoft’s previous music system, called “PlaysForSure.”

Zune comes in three colors: black and white, like the comparable iPod, and brown, a daring color for a consumer-electronics device, but one that has become popular in the fashion world. Each model also has a second color on a translucent band around its edge; the brown one is trimmed in green.

Placing the Zune next to the 30-gigabyte iPod provides a strong contrast. The iPod is thin, sleek and elegant looking. The Zune looks big and blocky, sort of like a prototype for a gadget, rather than a finished product. It is longer, thicker and heavier than even the 80-gigabyte iPod, which has more than twice its capacity.

Zune was adapted from a much-praised but slight-selling music player, the Toshiba Gigabeat, in order to get it to market more quickly.

The word “Microsoft” never appears anywhere on the Zune, only the new Zune logo and a cheeky, “Hello from Seattle” in tiny type at the bottom of the back of the device. The Zune’s tag line, evident immediately when you open the box, is “Welcome to the Social,” a phrase meant to stress the device’s wireless song-sharing feature, and to reach out to the Zune’s target market, young music lovers who build social relationships around favorite songs and artists.

But the wireless music-sharing feature on the Zune is heavily compromised, in a way that is bound to annoy the very audience it is targeting. Each song sent to your Zune from another Zune can be played only three times and is available for playing for only three days. After that, it dies and can’t be played again unless you buy it. Even if you play the song only halfway through, or for one minute, that counts as one of your three allowed plays. In fact, in my tests, a song I sent to my assistant’s Zune expired after only two plays, one of which lasted just a few seconds. Microsoft attributed that to a bug that it said would be fixed.

The Zune’s other big plus, the big screen, is similarly compromised. While it is three inches versus 2.5 inches for the iPod’s screen, it uses the same resolution. That combination can make images coarser and grainier. In my tests, on photos and videos, this didn’t matter much, and the Zune did a good job, even automatically switching into horizontal screen mode. But images of album covers often looked fuzzy, grainy and even distorted on the Zune when compared with how they looked on the iPod.

And for a product that’s all about “the Social,” Zune is curiously lacking a very popular iTunes feature — the ability to view and to listen to another user’s music library over a local network. This iTunes feature works in homes, office, college dorms, hotels, and other places, and it functions in mixed groups of Windows and Macintosh computers. But with the new Zune software, you can share your library only with Xbox game consoles, not other computers.

On the plus side, I really liked the interface on the Zune. In some modes, it allows you to do things with fewer clicks than the iPod does. For instance, if you are browsing through music, you don’t have to go back a step to switch from, say, a list of artists to a list of albums. Those choices are arrayed at the top of the screen and can be selected with a sideways push of the navigation pad.

Also, the entire interface is more colorful and visually satisfying than the iPod’s. Lists of albums are accompanied by thumbnails of their covers. Menus zoom in and out, and some are translucent. You can also select your own photo as the wallpaper or background for the device. But, unlike on the iPod, you can’t customize the main menu or go to “Now Playing,” or shuffle all songs with one click.

The Zune software also has a handsome look and feel. And it allows you to “guest synchronize” a Zune on another computer, something iTunes doesn’t allow. You can load songs from someone else’s library onto your Zune without wiping out your own library, though you can’t then transfer those songs back to your own PC.

But battery life on the Zune was very disappointing. Microsoft claims 14 hours of music playback on a single charge with the wireless feature turned off — the same as the comparable iPod — and 13 hours with wireless turned on. But Microsoft bases these claims on strict and unnatural usage conditions, such as never increasing the default volume, playing only one album over and over, and keeping the backlight on for just one second.

I tested the Zune in more normal conditions, shuffling through hundreds of songs, adjusting the volume where needed, skipping or repeating songs occasionally and using a 30-second backlight. In my test, I got just 12 hours and 18 minutes of music playback, versus 14 hours and 44 minutes from an iPod under the same usage pattern. With the wireless turned on, battery life on the Zune was worse — just 10 hours and 12 minutes, even though I didn’t send or receive any songs.

Overall, the iPod and iTunes are still the champs. Still, I expect the Zune to attract some converts and to get better with time. And this kind of competition from a big company with deep pockets and lots of talent is good for consumers in the long run.

Email me at mossberg@wsj.com.