Before You BuyHelpful Buying Guides

Excerpted from Buying a Computer For Dummies, 2006 Edition*

Desktop computers won their fame by being expandable. Laptop computers won their fame by sacrificing expandability for portability; you don't buy a laptop with the notion of "upgrading it later." You buy a laptop to have a computer anywhere you are: in a plane flying across the country, in a coffee shop, or in a bungalow over the lagoon in Bora Bora.

All the technical descriptions of a desktop computer apply to laptops as well: microprocessor, RAM, and disk storage, for example. Beyond that, laptops have special considerations that desktop users would never dream of. Chief among these are

• Microprocessors
• Battery life
• Weight
• Pointing device
• Removable or swappable drives
• Communications

Each of these considerations is discussed in the sections that follow.

Special (expensive) microprocessors

Laptops use special versions of the microprocessors used in desktop computers. These microprocessors are often physically smaller and use less power than their desktop brethren. They also contain the circuitry required to manage the laptop's battery. Because of that, they're also more expensive.

• It's the smaller nature of many of a laptop's components that make laptops more expensive than desktop computers.
• Other internal electronics in addition to the microprocessor are also smaller and use less power, which again adds to the price of the laptop.

Avoid laptops that use standard desktop microprocessors. Those chips use battery power quickly but also tend to get too hot for the laptop's tiny case. If in doubt, ask: "Does this laptop have a special laptop microprocessor?" (The numbers, names, and IDs for such microprocessors are too numerous to list here.)

Disk drives

Laptops come with very small hard drives, but don't let their size fool you. Often, a teensy laptop hard drive can store as much as its desktop counterpart. The difference in size is made up for by the price; tiny hard drives are expensive.

Forget about a floppy drive with your laptop. Instead, get – at minimum – a laptop with a CD-R/RW drive. That way, your laptop can read all CD disks as well as create its own CD-R or CD-RW disks.

Also consider the CD-R/RW and DVD-R/RW drives, such as the SuperDrive that comes on the Apple Macintosh laptops. These drives can read all the shiny media, both CDs and DVDs, plus write to CD and DVD disks. Again, you're going to pay a premium price to have it all.

A battery of issues

A laptop can use electricity from a wall outlet or its own, internal battery. The length of time the battery can power the laptop is, obviously, important. A fancy, high-end laptop may have impressive hardware statistics, but if you can use the thing for only an hour before plugging it in, you may as well lug around a desktop.

A good laptop should have batteries that power it for at least two hours, though six hours is better. Any quotes for longer battery life are most likely exaggerated. (Battery life tests are made under ideal conditions – not the same conditions under which you would be using the laptop.)

The best type of battery you can get is the lithium ion. Second best is nickel-metal hydride (NiMH). Both are rechargeable and can be recharged without having to drain them fully.

Avoid NiCad batteries. Although they're rechargeable, they suffer from the memory effect, which means that if you run on battery power, you have to fully drain the battery before it's recharged, or else the battery life gets cut short.

You may notice an interesting trade-off between laptop features and battery life. High-performance features drain battery juice quickly. So, if using your laptop unplugged is important to you, cut back on the RAM and microprocessor speed.

• Some laptops can "hot swap" batteries. That is, you use one for two hours and it drains. Then you can instantly replace that battery with another – without turning off the laptop. This process works only when the spare battery is fully charged.

Beware of laptops that claim longer battery life, yet measure that claim based on swapping batteries. You want to compare laptops based on the life of one battery at a time.

• If possible, try to use your laptop as much as possible without the batteries. Most laptop owners are adept at finding power sockets in airports, hotel lobbies, and restaurants. If you must, you can always rely on the batteries.

Charge your laptop's battery the night before you leave on a trip. That way, the battery is always ready to go in the morning.

• Many handheld and palmtop computers use standard flashlight batteries. Because those computers don't consume lots of power, they can operate for hours – sometimes days – on a pair of AA or AAA batteries.

The skinny on laptop weight

The ideal laptop weighs in at about 4 pounds. Even so, some models may push 10 pounds. The difference seems trivial now, but wait until you lug a laptop across O'Hare airport. You want to look light and carefree toting your laptop, not like you're trying to smuggle plutonium.

Note that laptops weigh more than their advertising boasts. What the manufacturers fail to mention is the weight of the portable AC adapter, spare batteries, and other add-ons. Consider all that when you buy.

The anti-mouse

Standard mice, although a great laptop addition, aren't always practical to have on the road. Therefore, laptops come with alternative pointing devices.

The most common anti-mouse is the touchpad. You touch this flat area, above or below the keyboard, with your finger to move the mouse. Clicking is done by either tapping the touchpad or pressing a button nearby.

Despite the usefulness of the touchpad, most laptop owners also carry a standard mouse. If they can find a nice surface to compute on, using the standard mouse is generally better than mastering the touchpad.

Laptop communications

All laptops are sold with standard dial-up modems as well as built-in networking through the standard Ethernet RJ-45 jack. Try to avoid any laptop that lacks either of these important options. (Note that laptops with wireless networking may lack the RJ-45 jack.)

Security issues

The same things that make laptops appealing to computer buyers also make them appealing to computer thieves: Laptops are easy to steal. To ensure against this problem, get a laptop that lets you attach a security device.

• The security device can be as simple as inserting a locking cable through the laptop's case. You can purchase a locking cable anywhere.
• Forget software passwords and encryption. Although that may protect your laptop's data, it's not the files on the hard drive that the crooks are after – it's the unit itself! Hard drives are often erased before the laptop is resold. You can do that whether or not your files are encrypted or password-protected.

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