Install a New Motherboard & CPU

1. Analyze your current PC

Before you do anything else, make sure your case supports the form factor (ATX, MicroATX, and so on) of the new board you plan to purchase. You’ll probably be upgrading your CPU at the same time, so make sure your new processor is compatible with your new motherboard.

Many older motherboards require a 20-pin main power cable from your power supply, but recent boards require both a 24-pin connector and a separate four-pin one. Your motherboard won’t work if improperly powered, so a new power supply could be in order.

Do your optical and hard drives connect via IDE (usually with ribbon cables) or via newer, thinner Serial ATA (SATA)? Many newer motherboards have only one IDE port (which supports two drives), whereas older boards have two. If you have more than two IDE drives, be sure your new board has a second IDE connector.

Be mindful of Windows’ licensing requirements—replacing a motherboard can necessitate reactivating Windows. Depending on whether you have a full-retail or OEM version, you may have to repurchase Windows.

2. Remove components and cables from your old motherboard

Speaking of Windows, you’ll need to decide if you’re going to install your new motherboard and keep your existing Windows installation in place, or take the opportunity to wipe your boot drive and start from scratch. If you do the second, have your Windows and application discs handy.

When you open your case’s side, take photos of your PC’s rear panel and interior, or label all the cables. (Sticky notes work well.) Many of today’s connectors are color-coded, but if yours aren’t, this precaution could prevent frustration later.

Remove any cards in your old motherboard’s expansion slots. Remove the screws securing them to the case, then pull the cards straight up and out. (For a PCI Express x16 card, you might need to depress a lever on the slot before doing this.) Place them on a clean, static-free surface.

Next, detach all cables and wires connecting your motherboard to the PSU, case front panel, optical and hard drives, or other components (such as fans). For the big PSU power-cable connectors that plug into the motherboard, squeeze a lever on one side to release the connector; most other cables should pull out easily.

3. Swap the old motherboard for the new one

Now for the switch. Locate the screws holding down the motherboard (usually six or nine), and remove them. Once done, the motherboard will lift out. To protect it, place it in the antistatic bag your new board came in. Next, pop out the I/O panel—the metal rectangle with the port cutaways—attached to the case. Your new motherboard will come with its own, designed for the board’s port arrangement. When inserting the new I/O panel, apply enough pressure around the edges to hear the clicks.

It’s more convenient to install the processor, its cooling fan, and the RAM before installing your new motherboard. RAM is easy: Lower the levers on the RAM slots, line up the notch in the module with the slot’s protrusion, then press the chip until both levers lock.

Processors are more complicated. Intel’s and AMD’s designs vary, sometimes between their own lines, but today’s processors and sockets are keyed so it’s hard to orient a CPU incorrectly. That said, never force anything: If your processor resists when you engage its locking mechanism, you could damage it. Once it’s in place, apply a layer of thermal paste to the CPU, and attach the fan to the board, covering the CPU. Don’t forget to plug in the fan’s power cable to the board’s “CPU fan” header.

If your new motherboard is the same size and shape as the old, you shouldn’t need to adjust the standoffs that keep the motherboard from touching the case. If, however, you’re upgrading from a smaller board to a larger one, you might. Place the motherboard in the case, lining up its holes with the standoffs. Make sure there’s a standoff for every hole, and vice versa. After the standoffs are settled, gently place the motherboard, fitting its ports through the I/O panel. Once the holes are directly over the standoffs, secure it using the screws removed earlier.

4. Attach old components to the new motherboard

Reconnect all the components you disconnected in step 2. Slide each expansion card into its appropriate slot, and screw it down. Cover any unused openings with a blank spacer.

Most interior cables are keyed to connect only one way, so replacing them should be easy. If you’re unsure where certain connectors live on the new board, consult your manual for a diagram. Take special care with USB and FireWire cables—mixing these up could cause system-crippling problems.

The front-panel connectors can trip up even the experts. For your power/reset switches and activity lights to work, you need to match up the connectors with the proper pins and orient them correctly. Your motherboard manual will explain the proper layout, but a little trial and error may be required.

5. Finishing up

Close the case, re-attach the rear-panel cables, and turn on the computer. It should boot, and you’ll see your new motherboard’s splash screen. Follow the instructions to enter the BIOS. There, check the drive and RAM configuration to make sure everything’s recognized, set the boot-device priority, and enable USB 2.0 or PCI Express support, if your board requires it. Save any changes.

Then, assuming you aren’t reinstalling Windows, boot for the first time. Windows will need to install drivers for the motherboard, most of which it can and will do automatically, though you might need the CD that came with your board.

If you’ve gone the Windows-reinstall route, put your Windows CD into the optical drive, direct the BIOS to boot from it, and follow the prompts to reinstall the OS.