The Laptop-Buying Learning Curve

Shopping for a laptop is either too easy or too hard.

If you just need a semi-portable machine to move from room to room in your house, without ever untethering it from an electrical outlet, you can't go too wrong with shopping by price alone or some obvious factor such as screen size.

But if your laptop will exit home on any regular basis -- say, if you're a student looking at years of toting the machine from dorm to classroom -- you have far more things to contemplate. And the two most important factors among them, a laptop's weight and battery life, are either routinely hidden in marketing materials or not published at all.

Some manufacturers have good reasons to hide those details, lest they be embarrassed by them. Others may just be deeply confused as to what people want in a portable computer. There is no perfect laptop for everybody, but there may be a perfect one for you -- depending on what you value most in a machine.

The stickiest of these value judgments remains that old standby: Mac or Windows?

The basic trade-off between Mac OS X and Windows XP has changed dramatically since Apple began selling computers that run on the same Intel processors as many PCs. A Mac can now run every single program a PC can, once you install Apple's free Boot Camp software and use that to load a copy of Windows XP on the Mac's hard drive. (Or you can buy "virtualization" software that runs XP in its own window in OS X.)

Instead of having to balance Apple's security and ease of use with the far wider choice of software provided by Windows, you can have both. So if you've been leaning toward getting a MacBook, Apple's consumer-oriented laptop, but worry that you might have to run some Windows-only program -- go ahead and get the Mac.

Windows laptops still offer cost savings -- at least before you pay for a security-software subscription -- and most offer more expansion options than any of Apple's portables.

Many of the cheapest Windows portables are "desktop-replacement" laptops meant to stay anchored to desks -- some of these beasts weigh more than a dozen pounds. (Apple doesn't sell anything in that category at all.)

Avoid the desktop-replacement models if there's any reasonable chance that your laptop will regularly move across campus or across town. In those cases, you probably won't like anything weighing much more than five pounds. (You can get a laptop that weighs a lot less, but good luck finding one for anything under $1,500.)

Don't forget the power adapter, which can add almost a pound in some cases. You may also need to factor in upgrading to a higher-capacity battery: Many manufacturers try to keep a laptop's cost and weight down by including only a starter-sized battery that won't make it through a two-hour DVD movie. (A good laptop should finish a 2- 1/2 -hour DVD before conking out.)

As a general rule, if the company's Web site offers a choice of batteries, you should probably trade up from the standard one.