How to Replace a Hard Drive

Time For a New Hard Drive?

To remove the old hard drive from a desktop computer you will first have to open the system unit case. Most cases are secured with Phillips head screw-nuts at the back of the case. Once these are removed, you can slide the case off easily.

Next, unplug the data cable and power cable from the old hard drive. The data cable may be a wide, flat grey ribbon cable or a modern, slim SATA cable that has a telephone-style clip jack on its end. The data cable can be traced to a connector on the motherboard. The power cable will be a connector and a foursome of wires which you can follow back to the power supply. Unplug both from the drive, and move them out of the way. Need we mention that you should unplug the whole computer from the wall electrical outlet first?

For a desktop computer, the size of the drive bay is important to note. The drive bay is the slot in a short rack inside of your computer into which a hard drive and its carrier (if any) fits. Some desktop computers have drive bays that are 5-1/4 inch wide. However, most hard drives today are only 3-1/2 inches wide. If you have 5-1/4 inch drive bays, make sure that the new hard drive you buy comes with a 5-1/4 inch carrier - a metal adapter frame into which the 3-1/2 inch drive can be secured and whose external sides fit the 5-1/4 inch drive bay perfectly. If your current hard drive is 3-1/2 inches wide, it may be in a carrier that you can reuse.

The old hard drive or its carrier will be secured to the rack by small screws on the rack's sides. Use the right size screwdriver to remove these tiny screws; if you strip them, your new hard drive will not be secured reliably. Put the screws in a small cup or tape them together so none gets lost.

Slide the old hard drive out of the rack, exerting steady pressure from the front of the case and pulling on the sides of the hard drive from the rear.

In some cases, especially the compact desktop models that sit flat on the desk, the components are packed pretty tightly, and you may have to remove a retaining bar to gain access to the hard drive. But you should never need more than a screwdriver to do the job. If you find yourself tempted to employ a crowbar, sledgehammer, or any power tools, take a few deep breaths. Re-examine the case, frame and all the screws that hold things together. The path to the removal of the hard drive should become clear.

Installing Your New Hard Drive

If necessary, remove the old hard drive from its carrier and screw the new hard drive into the carrier. Now comes the fun part: setting jumpers.

If you have only one hard drive, or if your computer uses modern SATA hard drives, you can probably skip this step. Older IDE hard drives come with their jumpers pre-set to be the "master" or boot drive. But if the drive you are replacing is a secondary or "slave" drive, then you will have to pry up tiny plastic blocks called jumpers and move them around to cover specific pairs of pins in an array of pins. Illustrations of the correct jumper placements for master, slave, and "auto-discover" are generally printed on a hard drive. ("Auto-discover" means the computer will detect whether a drive is the master or slave automatically.) If the jumper positions are not spelled on the label, or the accompanying documentation, a bit of Googling should help you find the correct settings for your drive.

Slide the new hard drive into an empty slot in the rack. Carefully line up the holes in the sides of the carrier or drive case with the holes through which the securing screws go. Put the screws back in.

Plug in the power and data cables. Replace the case. Plug in the computer's power supply. Partition and format your new hard drive, if necessary. For help with partitioning, see my companion article on Partition Managers.

Notebook computers are a bit easier. They generally come with only one hard drive to save space and weight. Typically, there is only one screw to remove that releases a cover over the hard drive bay. Then you pull out the old drive, slide in the new drive, and replace the cover. Partition and format the new drive.

Consider keeping that old hard drive, and converting it to an external hard drive. Buy a hard drive enclosure kit for around $30, pop in the old drive, and connect it to your computer with a USB cable.

If not, take care when discarding a hard drive. It's not uncommon for people to toss a hard drive in the trash, even one that they thought was broken; only to have it - and all their private files - recovered by a dumpster-diving delinquent. For some tips on wiping your hard drive clean or discarding it in a secure manner, see my Clean Hard Drive. article.

If your new hard drive is going to be your boot (startup) drive, you'll need to pop in your installation CD and load the operating system onto the drive. You might also want to transfer all the files from the old drive to the new one. For help with that, see my article on creating a Hard Drive Backup Image.

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