Turn off your PC; unplug it from the wall; and disconnect the mouse, keyboard, monitor, printer, and any other external cables (such as USB). Remove the PC's cover, and carefully look at what you need to remove or disconnect to reach the motherboard. In some cases, you'll have to remove a hard drive or other hardware to get to the motherboard.
Before you begin working under your PC's hood, put on an antistatic wrist strap (available from a local electronics supply store such as Radio Shack) and clip it to a grounded metal object.
Remove the screws holding the add-in cards, carefully remove the cards, and lay them on a clean, flat surface, preferably in the order in which you removed them.
Label each cable with masking tape and write down each connection as you remove it. Unplug the power connector, the floppy disk cable, and the EIDE connectors. Make sure to note which cable is connected to the primary and which to the secondary EIDE connector (sometimes they're marked Channel A and B, or 1 and 2).
Finally, unplug the small connectors attached to the front-panel switches and LEDs (not shown below).
2. Remove the Old Motherboard
Most motherboards are attached to the case with a handful of screws--usually about five, but the number can vary. Find them, carefully remove them, and set them aside in a handy container, such as a coffee cup or that ashtray you don't use any more.
Remove the old motherboard by sliding it slightly toward the front of the case (so the connectors at the rear are clear of the case) and then pivoting it upward.
3. Install the RAM and Processor
Before you mount the motherboard in the case, insert your new RAM module (or modules) into the RAM socket (A), beginning with the socket marked "Bank 0." DIMM modules fit only one way. Slide them firmly into their sockets. Brackets on each side will snap into place automatically when the module is correctly seated.
Most of today's CPUs fit into sockets. To install a socketed processor, lift the lever on the socket and carefully insert the CPU (B), making sure that Pin 1 on the CPU matches Pin 1 on the socket. Hold the processor firmly in place and lock the lever down. If you're installing an older CPU that fits in a slot, carefully insert it until it's firmly seated.
A reminder: All CPUs need cooling. If a heatsink or fan isn't built in, purchase and install one. Without it, your new CPU will self-destruct in minutes.
4. Install the New Motherboard
Slide the new motherboard into the case. You'll know it's in the correct position when the mounting holes align.
Mount the motherboard, using the screws you removed in step 2. Just "snug up" the screws; screwing them in too tightly can damage the motherboard.
5. Reinstall Cards and Cables
Reinstall the cards and cables that you removed. Don't rush through this step! Work slowly and carefully, avoid bending pins, and double-check to see that everything is correctly connected.
IMPORTANT: Don't forget to connect the CPU fan's power cable to the motherboard.
Reinstall your PC's add-in cards, securing them with the screws you removed earlier.
Reconnect the mouse, keyboard, monitor, printer, and any other external devices you may have, but don't put the cover back on your PC until you're absolutely sure that everything's working.
Finally, plug in the AC power cable.
6. Start It Up
Turn on your PC. If it beeps and you see messages on the screen, that's a positive sign. Expect the new hardware to confuse Windows initially. The OS should automatically reconfigure itself, but don't be surprised if Windows restarts itself several times during the process.
If nothing happens--or if your PC hangs part of the way through start-up--turn off your PC, disconnect the AC power, recheck all the connections, and start the system up again. If it hangs again, contact your motherboard maker's tech support. Dead-on-arrival motherboards, CPUs, and RAM modules are rare, but they do occur.
Enjoy
