"Dollar for dollar you'll get more power and features in a PC assembled by a big company than in one you build yourself." That's the conventional wisdom. But new standards and improved component integration that packs more functions into fewer parts now allow you to build a modern system for the same cost as a similarly equipped retail PC.
To keep things simple, we bought all of our items from a single supplier. Limiting the number of sources for your components may reduce your shipping costs and save you time, and it's less aggravating to place and track a single order.
1. Get ready: To protect the components from damage, keep them in their antistatic packaging until you're ready to put them in place. Wear an antistatic wrist strap clipped to a bare metal spot on the chassis, or touch the chassis frequently to equalise your charge relative to it. Handle the motherboard, processor, memory modules, and other sensitive parts by their edges only, and don't touch any socket or connector pins. Finally, make sure the system is unplugged until you're ready to start it for the first time.
2. Prepare the chassis: Take the cover off the chassis and remove any instructions, assembly hardware, or loose cables inside the case. If the chassis has a removable motherboard tray, take it out. Remove the I/O shield from the connector area by pressing inward on the shield until it pops into the case. Locate the I/O shield that came with the motherboard and snap it into the connector area in the chassis from the inside out.
3. Add the motherboard: As you place the board into the chassis, align the rear-facing connectors with the holes in the I/O shield. If your case uses a motherboard tray, install the processor and memory onto the motherboard first, and then slide the board and tray securely into the chassis.
With the tray removed from the case, set the motherboard atop the mushroom-shaped standoffs at a slight angle from the front of the board to the back, and then press down until the standoffs protrude through the holes in the board. If your chassis uses conventional screws to hold the motherboard, you may have to move or install brass standoffs to match the pattern of holes in your motherboard. Once that's done, set the board down over the standoffs until they line up with the holes, and install the screws to tighten the board.
4. Place the processor: If you are using an Intel processor, install it in the LGA (land grid array) socket on the motherboard. Conventional CPU designs put the pins on the processor, but LGA has them in the socket instead. In either case, don't touch the pins or contacts: They are very delicate and prone to physical and electrostatic damage.
LGA775 sockets, such as the one on our motherboard, use a lever to clamp a load plate over the top of the CPU. Disengage the lever from the latch, raise the plate, and remove its plastic cover.
Remove the plastic cover from the processor to expose the contacts on the bottom. Hold the processor by the edges and locate the pin-1 indicator and orientation notches on its sides. Line up the notches in the chip with the orientation keys in the socket. Close the load plate over the top of the processor, and clamp it down.
5. Keep it cool: To attach the heat sink to the motherboard, align the four fasteners with the holes in the motherboard and press each fastener down until it clicks. AMD heat sinks have four clips that click into place before you lock their levers. Make sure the fasteners are fully seated and the heat sink's base is flush against the motherboard.
Connect the CPU fan to the proper head on the motherboard. LGA775 processors use a new four-wire fan connector with an extra signal that allows the motherboard to control the fan speed. Plug this connector from the heat sink into the four-wire "CPU FAN" connector on the motherboard; normally this connector is next to the processor socket.
6. Don't forget the memory: Our system uses two 512MB modules for a total of 1GB of RAM. To operate in dual-channel mode on our motherboard, we installed this pair of modules in the blue sockets.
To install DDR2 modules, open the locking tabs to the side and then insert the module into the socket so that the notch aligns with the tab. Press the module firmly straight into the socket until the tabs lock the module into place.
7. Insert the add-in cards: Next, install your video card and any other add-in boards by removing the slot cover, inserting the card firmly in the appropriate slot, and securing it using either the screw from the slot cover or the appropriate card retention mechanism in your case.
8. Park the drives: Pull the locking levers on each side of one of the lower 3.5-inch bays forward (away from the chassis). Slide the drive into the bay with the connectors facing back. With the drive in place, press the locking levers inward. Don't install the cables yet. With some cases, you use four screws to secure the drive. Accessing these screws in the tight quarters of a case is a major cause of scraped knuckles, which explains manufacturers' shift to levers.
9. Add a DVD burner: Slide the locking lever of a 5.25-inch bay to the unlock position, place your DVD or other optical drive into the bay, and, once it's fully seated, relock the lever. As with the hard drive, don't connect the cables yet. Note that some cases hold the drive with external locking clips.
10. Adjust your cables: On the front of the chassis are a power switch, reset switch, power LED, and hard-drive LED. Find the cable for each and plug it into the appropriate front-panel switch/LED connector on the motherboard. Look to your motherboard's manual or the legend printed on the motherboard for guidance.
Next, locate the internal USB, FireWire, audio and other I/O connectors on the motherboard and attach their cables to the appropriate ports. The assorted cables and connectors should be keyed to prevent improper installation, but consult the diagrams in your motherboard's manual to be sure that you have all of the cables and connectors matched.
Now connect the data cables to the disk drives. The 80-conductor ribbon cable attaches the parallel ATA port on your motherboard to the DVD drive, and the thin Serial ATA cable links the first SATA port on your motherboard to the hard drive. SATA cables plug in only one way. If the ribbon cables aren't keyed, note the odd-coloured pin-1 wire, which matches up to the small triangle or pin-1 indicator marked on the motherboard and drive connectors. Once you have the cables attached, route them so they are out of the way and do not interfere with airflow through the case.
11. Add the juice: Plug the large 24-pin main power connector and the 4-pin 12V connector into the motherboard. The DVD drive uses a single 4-pin peripheral power connector, while the hard drive uses either a 4-pin peripheral power connector or a 15-Pin SATA power connector. Route the cables out of the way inside the case, and neatly bundle or tie off any remaining unused power connectors to keep the airflow unobstructed.
The chassis we used in our PC has a large, 120mm rear-mounted fan for added cooling. Plug the three-wire connector from your fan into the matching "REAR FAN" connector on the motherboard. Some case fans also take a standard 4-pin peripheral power connector.
12. Link outside the box: Attach your display, keyboard, mouse, and speakers to the appropriate colour-coded connectors on the back of the system.
13. Turn it on: Attach the power cord and press the power button (don't forget to power up your display too). Insert the Windows XP CD-ROM and allow the system to boot from it. When you are satisfied that everything works, close the case by reattaching the chassis front and side panels.