Buyers beware: what to look for when purchasing a new PC.

"There's a technology conspiracy being perpetrated by computer hardware and software companies," says Ronald McKenzie, president of 3 Tier Client/Server Systems Inc., a computer consulting firm in Englewood, New Jersey. These companies, he warns, are out to get you to buy computer devices and components that you may never need, solely for the sake of being state-of-the-art.

Many computer resellers contribute to the fleecing of the general public by employing hard-nosed salespeople whose goal is to sell you any system-not necessarily the one that's right for you. But the consumer is not without blame. By failing to educate ourselves about the components integral to a computer's performance, we consent to our own deception, explains Stephen Thomas, president of Panorama Computing Inc., a Cleveland-based computer consulting firm.

The first decision to make is whether to buy an IBM-compatible or an Apple Macintosh. "You should purchase a Mac if your livelihood is strongly dependent upon a computer, and you are in the music and creative arts field or doing video or film editing," says McKenzie. But McKenzie and Thomas agree that most people should lean toward purchasing IBM-compatible machines.

For most consumers, the question becomes, What attributes must my IBM-compatible PC have to perform a wide variety of household, business, entertainment, educational and multimedia activities? It's not so much what you need the computer to do now, but whether it'll be able to handle the more challenging applications that will inevitably arise. The cost of a fully equipped home computer will likely be in the $1,800-$2,800 range. Of course, you can sacrifice some aspects for a lower price, but this will increase the likelihood that you'll have to upgrade sooner. A complete home system should have a life span of roughly five years. Here are the key components to keep in mind:

CPU (central processing unit). Every few months chip manucfacturers like Intel introduce a smaller, faster and stronger chip. 200 MHz Pentium-powered chips are now available. The cost increments are generally proportional to the speed of the chip. For instance, a 133 MHz Pentium-powered computer will run applications roughly 10% faster than a 120 MHz machine for roughly 10% more money.

For most home and small office users, a 120 MHz PC will satisfy your needs. But speed demons may find the power boost is worth the extra cash. A 200 MHz Pentium will definitely scream, but how fast do you really need to run a spreadsheet or word processing application? People who use graphically intense applications will reap the benefits of high-performance Pentium chips. Graphic artists and CAD designers will find that a machine running at 200 MHz will significantly reduce crippling wait times for data to transfer.

The speed at which a computer runs graphic-intensive applications also depends on its local bus speed--the rate that the CPU communicates with the hard drive. Many of these applications have huge memory requirements, thus making it necessary to swap from RAM--which is stored on the motherboard with the CPU--to the hard drive for added processing space. When this happens, your computer moves only as fast as the local bus speed will allow--around 33 MHz--unless you have special hardware add-one.

Intel's Pentium Pro line, available in 133 MHz, 166 MHz and 200 MHz, comes with default local bus speeds of 66 MHz. This will make a significant difference, but nearly double the cost of the system. Machines with the same CPU speeds will also be available with the 33 MHz local bus speed, so be sure to check them out, especially if you need the added speed that a Pentium Pro will provide. Cyrix and AMD manufacture CPUs that perform comparably to the Intel chip.

System memory: 16 MB is optimal. Though operating systems such as Windows 95 can run with 8 MB of RAM, memory prices are low and it doesn't add much to the total cost of the machine.

Expansion bus: These are the connections between the computer's motherboard, which houses the CPU, and peripheral devices, such as CD-ROMs, installed in the system. New machines are equipped with no less than eight expansion slots, says McKenzie. It's important to determine how many ISA and PCI expansion slots your machine has. ISA slots communicate with your CPU at 8 MHz and PCI slots communicate with your CPU at 33 MHz.

Hard disk: One gigabyte is standard on many new machines, and it's better to have space on your hard disk, than to need it.

CD-ROM: A 6X CD-ROM drive.

Sound card. A minimum of 16-bits; a 32-bit sound card is necessary only for users heavily into the production of music.

Video card: 2 MB if you intend to use graphics, multimedia applications or graphically intense video games. Otherwise, 1 MB should suffice.

Monitor: 17-21-inches if you intend to use intense graphics. However, if you are doing mostly text applications, a 15-inch monitor will do. Also, 17inch and larger monitors can be used with IBM-compatible or Mac systems.

Modem: 28.8/14.4 data/ fax modem. People who plan to spend over five hours a day on the Internet should consider an external modem. It's connected to a serial port and transfers data at 33 MHz, compared with internal devices that offer a transfer rate of 8 MHz. External modems are also compatible with any computer platform.

Service and support: A one-year warranty with on-site service is standard. These can be extended for an additional fee, usually $200-$300 for an extended three-year warranty with on-site service. A toll-free technical support hotline is-important; also be sure to find out if that support is around-the-clock. Compaq, Dell, Hewlett-Packard and IBM are among the highest rated companies for service and reliability.