Everything you need to know about buying the perfect laptop

Perhaps no common computer product has as many variations, with as wide a performance range, as the modern laptop PC. From tiny netbooks to big and powerful desktop-replacement systems, the differences in pricing, features, and performance are staggering. Follow our comprehensive guide to make sure you get the laptop that’s right for you.

Buying a new notebook can be tough because you have so many options to consider, and no shortage of reasons for purchasing one. Maybe you’re about to head off to college and you need to take notes in class. Perhaps your current laptop labors when running today’s applications, and it’s time for an upgrade. Or maybe you’re happy with your desktop PC, and you want a companion device for surfing the Web from your couch. Even if you know what you want to do, with so many laptop models available it can be hard to decide among them. The potential for confusion is enough to make you choose something that just looks cool or happens to be available on your warehouse store’s shelf–but that approach can end in heartache.

Ultimate guide to buying the perfect laptop for business

Three big-screen laptops for small-scale budgets

It’s best to start by deciding which category of laptop you’re most interested in. Laptops fall into four main categories: netbooks, ultraportables, all-purpose laptops, and desktop replacements.

The laptop category that is right for you depends on the kind of user you are.Once you have decided on a category of laptop, it’s time to start considering the specs.

For their intended purpose, netbooks are a great choice. They aren’t powerful enough to do everything you need a PC to do, but are rather meant to be companions to your main PC. Small and light enough to carry around all day, they’re the perfect device for taking notes in class or surfing the Web on a commuter train. A typical netbook weighs about 3 pounds or less and has a screen size of 6 to 10 inches. Most cost around $300 to $400.

Top tips on buying a nifty Netbook … at the right price

If you’re seeking a new primary PC, you’ll want to look elsewhere. Netbooks’ limited screen resolutions (10-inch netbooks typically top out at 1280 by 768), RAM, and processing power make editing photos and spreadsheets a pain. In addition, some Web pages, Flash games, and applications simply don’t fit well on a small screen. Still, there’s something to be said for a system with a battery life of 6 or more hours; in our PCWorld Labs tests, that’s how long most of the newest netbooks last.

Most netbooks are based on Intel’s Atom line of processors. These chips can run the standard Windows operating system you’re accustomed to and all your usual applications, but they’re not very fast compared with more-expensive Intel CPUs such as the Pentium Dual-Core and Celeron found in ultraportables, or the Core 2 Duo and Core i5 found in all-purpose or desktop-replacement laptops. Couple this limitation with the fact that netbooks typically have only 1GB of RAM (very few offer 2GB as an option), and you’re looking at pretty slow performance.

A netbook is fine for simple Web browsing or word processing, but it struggles on streaming video, editing photos, or running multiple applications simultaneously. And if you’re thinking of playing 3D games, forget it: The majority of netbooks use Intel’s integrated graphics chips, and not very good ones, at that. Some netbook models may have one of nVidia’s Ion GPUs (graphics processing units), which are a lot better at handling graphics and decoding video, but even these won’t play the latest and greatest games well, especially in combination with the low-power Atom CPU and limited RAM. Alternatively, some netbooks now supplement their Intel GPUs with a Broadcom decoder chip that does nothing but speed up video playback and improve its quality; if you want to use your netbook to watch a lot of Hulu or YouTube videos, you may want to pay a little extra for this option if it’s available.

One more drawback: Netbooks almost never have an optical drive, so you can’t play DVDs or load software off a disc without buying and using an external, USB-attached DVD drive.

Slim and light, ultraportable laptops are a step up from netbooks. Sure, in choosing an ultraportable over a netbook you tack on maybe a pound of weight, but that added weight means a more powerful processor, more RAM, and often a larger screen. These systems are ideal for users who need a fuller PC experience but still want a machine that’s easy to carry around. Screen sizes vary, from around 11 inches to 14 inches, but models with larger screens are usually considered “ultraportable” only if they’re especially thin. You can expect an ultraportable to weigh from 3 to 4.5 pounds, typically; battery life extends from 4 to 6 hours. Prices generally land in the $600-to-$800 range, but some superthin models with larger screens can cost more than $1000.

Compared with netbooks, ultraportables have more processing power. Ultraportables use either dual-core CPUs–the same as you might find on an all-purpose laptop–or low-voltage processors from Intel or AMD that aren’t as powerful as what you find in bigger notebooks (or more expensive ultraportables) but are far more capable than Atom netbook processors. Most ultraportables have 2GB to 4GB of RAM, too. As a result, ultraportables perform a lot better than netbooks on everyday applications, and they’re far more suited to running multiple applications at once.

In the name of saving weight, cost, and battery life, many ultraportable laptops stick with integrated graphics chips that lack the oomph to handle modern games or video decoding. Still, it’s not too hard to find ultraportable PCs with dedicated GPUs from nVidia or ATI; typically these laptops are powerful enough to run modest 3D games, and they do an excellent job on accelerating video.

If you’re interested in playing DVDs, or if you often need to load software from a disc, you’ll want to make sure to look for an ultraportable with an optical drive. In slimming down, many ultraportables these days have omitted the optical drive, but you can find some models (typically the pricier ultraportables with dual-core CPUs) that incorporate them (unlike netbooks, which eschew the optical drive entirely).

Models in the all-purpose laptops category are, well, all-purpose: They’re large and powerful enough to serve as your everyday computer, but portable enough to accompany you when you’re on the go. This category has more options than almost any other class of laptop. You can find durable ruggedized laptops for business travel, convertible laptops with reversible screens that turn them into tablets, gaming laptops, cheap notebooks, expensive and stylish laptops, and more.

Generally an all-purpose laptop is defined as a system with a screen from 14 to 16 inches, and weighing more than 4.5 pounds. Most of these models use full-power dual-core and quad-core laptop CPUs (as opposed to ultra-low-voltage processors or Intel’s energy-sipping Atom CPUs), and you can expect even entry-level systems in this category to have about 4GB of RAM, often with options for up to 8GB. The weight can vary widely depending on the model and configuration, but 5 to 8 pounds is common.

You’ll find a wide range of prices as you shop for a general all-purpose laptop. Low-cost models can be as cheap as $400, but piling on extra options or choosing a system with a sleeker body or a better processor and graphics configuration can drive the price to $1500 or more. Optical drives remain standard, and Blu-ray Disc drives are optional on many all-purpose laptops.

You can get an all-purpose laptop with almost anything you desire, if you’re willing to pay for it. Some have integrated graphics, others have drastically more powerful discrete mobile GPUs that will let you play the latest 3D games. Want a Blu-ray drive and an HDMI output so that you can hook the laptop to your HDTV? Some models have those features. Looking for 1TB of hard-drive space? You can get that, too. A touchscreen? Check. The array of features and options is dizzying. Manufacturers sometimes prepackage sets of features into specific laptop models for sale, whereas companies such as Dell, Fujitsu, HP, and Lenovo give you some level of customization of your laptop, so you can buy a configuration that best matches your needs.

Larger screens and more-powerful processors mean shorter battery life, though. Most all-purpose laptops last from 2 to 5 hours on a charge, depending on the model and how you use it; playing games and using Wi-Fi drains the battery faster than light Web surfing does, and cranking up the display’s brightness shortens battery life considerably.

A desktop-replacement laptop (also known as a power laptop) is just what it sounds like: a larger laptop aimed at people who need the performance and large display size of a desktop computer but want to be able to move the machine from room to room easily. Screen sizes start at 16 inches and go up to 18.4 inches; models with higher screen resolutions are ideal for photo or video editing.

Don’t expect to carry one of these notebooks around with you all day, though–typically they’re too large to fit in a regular backpack, and at 8 to 12 pounds they’re tough on the shoulders. Consider these laptops as being more “luggable” than “portable.”

The processors in these beefy laptops are typically top-of-the-line, either dual-core or quad-core chips whose performance rivals that of the CPUs found in all but the most powerful desktop computers. Discrete graphics chips from ATI or nVidia are standard on most desktop replacements, too. If you pick the right power laptop, you can play even the most demanding modern games. As for the amount of RAM, 4GB is the bare minimum. A hard drive of 500GB or more is common, while some laptops have up to 1TB of storage.

Of course, all of that power comes at a price. The battery won’t last long (typically 2 hours or less with heavy use), so you shouldn’t stray too far from an outlet. The high-power CPUs and GPUs run hot, too, making it uncomfortable to rest a desktop replacement notebook on your lap. And then there’s the literal price: Cheap models may cost $1000 or less, but a nicely loaded desktop replacement will easily push $2000 or more.

This category is really for two types of people: Gamers, who need tremendous CPU and GPU power to play the latest titles, and professionals (such as video editors, photographers, or engineers) who need large displays and lots of horsepower to do their work.