How To Physically Install A Second Internal Hard Drive

step5a 300   How To Physically Install A Second Internal Hard DriveWhen you find yourself running out of hard drive space, you can either delete something or add some more space. While an external USB hard drive is an easy plug and play option, it’s not really ideal – they take up disk space, possibly an extra power socket, use up a valuable USB port, and are generally slower than internal drives. Let’s take a look today at the more difficult option of adding a second internal drive.

Now would be a great time to download our new guide – Your PC, Inside And Out – to familiarise yourself with the basics of your computer. We’ll be focusing only on the hard drive today, but the guide will give you a great overview on all the random sockets and ports you’ll see on the motherboard once you’ve cracked it open.

Step 1: Identify If You Can Add Another Internal Drive Or Not

Not all computers are built equal, unfortunately. If you have a laptop, or an all-in-one machine where the system internals are hidden behind the monitor – then your only option is to go with a USB drive and you really shouldn’t think about opening it up. If you have a slim desktop then read on, as there is a chance you will have enough room for a second drive. If you have a mid to full size tower, then you should be able to easily add a second drive, or two, or three! Refer to the chart below if you’re unsure.

second drive   How To Physically Install A Second Internal Hard Drive

Step 2: Backup

Although we’re not anticipating any problems, it’s good practice to back up your crucial data before doing any kind of hardware alteration. We’ve covered some great options for backup here, and here in our directory.

Step 3: Open The case

Before going any further, unplug the power from the case and all peripherals.

Most tower cases can have their sides removed with just two screws. You need to remove the side which doesn’t have the motherboard on it, so look at the back of the system, find the USB/mouse ports, and remove the OPPOSITE side.

back   How To Physically Install A Second Internal Hard Drive

Step 4: Get Rid Of Any Static Electricity In Your Body

When touching the insides of a computer, technicians use a grounded wrist-band to reduce the risk of shocking any delicate components with the static electricity stored in the human body. For our purposes, touching a radiator will suffice.

Step 5: Find The Hard Drive & Connectors For It

The insides of all computers are quite similar, and you can read the PDF guide for a full breakdown. The hard drive is a fairly sizeable chunk of metal like this:

   How To Physically Install A Second Internal Hard Drive

You should find it sitting in a metal cage of some sort. Check now to see if you have room to fit another one in there. A tower case will normally have space for up to 3 or 4 drives, but a smaller desktop system may have only been designed to take one drive, in which case you’re out of luck and will need to consider either upgrading the one already there, or using a external USB drive instead.

Step 6: Identify If You Have A SATA Or IDE Drive

Look at the following picture and compare it to your drive. If yours is of the type at the top, with a wide ribbon cable – it’s a very old connection type called IDE. Ideally, yours will be SATA. If you do find yourself with an IDE drive, you’re not completely out of luck but I’m afraid it’s out of the scope of this guide. IDE drives are becoming increasingly harder to buy, and it’s a good indication your computer is really getting old.

sata ide lg   How To Physically Install A Second Internal Hard Drive

Check out the things plugged into it. One will be power. There are two possible types of power cables, and you will of course need to find a spare one in your system that you can use. These might be tucked away somewhere, so follow the other power cables carefully and try to find a spare one.

power   How To Physically Install A Second Internal Hard Drive

Some hard drives can take either kind of cable, but the SATA type are easier to plug in so I use those if available. If you have a spare power cable but it isn’t SATA, you can still get a second drive but you’ll need to make sure it can accept a MOLEX type power cable, or you can get a MOLEX to SATA adapter for under $10.

Next, follow the SATA data cable (not the power one) to the motherboard, and have a look at where it is plugged in. Different motherboards have different numbers of SATA ports, and older machines may even only have one. Obviously, if you can only find one SATA port, then you can only plug in one SATA drive drive. If you can see some spare sockets, then congratulations – you can now go buy a second drive!

   How To Physically Install A Second Internal Hard Drive

Step 7: Buying A Drive

There is very little between drive manufacturers, and most hard drives that develop a fault do so within the first week of use. On the technical side, you are looking for a “3.5 inch SATA hard drive”, and make sure you pick up another “SATA cable” while you are there – the store clerk should able to help you with this if you can’t find one.

Step 8: Install

Sliding the drive into the cage is the hardest part as sometimes it can be blocked by a large video card or other cables. Identify the cables before you actually go ahead, noting which sides face up (SATA data and power cables all have a little notch on one end which means that inserting it the wrong way around is virtually impossible).

Once seated in the drive cage, use the screws that came with the drive to secure it – you will need to align the holes on the drive with the holes in the cage or tray. Next, find the spare power cables and the SATA cable, and plug those in. Replace the side, and power up the machine.

I’ll be covering the software and configuration side of adding a second drive in my next article – so stay tuned for that. As ever, feel free to ask any questions in the comments and I’ll do my best to answer.

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Dave Drager

Just a note – some of the larger laptops do have a second hard drive bay where you could install a hard drive. Most do not, but you never know. Put it in the ‘maybe’ category. :)


there are also kits for some notebooks that allow you to replace your dvd-drive with a second hdd.

James Bruce

Good point, Dave too and Bla. I really wanted get one of the those second drive kits for my old macbook pro since the DVD was shot anyway, but they were sold out at the time so I got a 27″ iMac instead (figure the logic on that one out!)

I chose to write not-upgradeable though as that will cover 95% of cases, but thank for bring that up you two.


Have a look on ebay for hard drives both ide and sata, both still fairly easily available and installation of an ide drive is not much harder – if at all than a sata drive! Just because a computer is old doesn’t mean you have to junk it if all you need is more ram or more hard drive space.

This is nevertheless a very useful guide and very clear so thank you for it
(I have bought several drives and they haven’t had screws again check ebay or your local repair shop for a small price – if in doubt ask before you buy)

James Bruce

You’re right. IDE drives are pretty much the same really, except for maybe having to think about the whole master/slave cable bit. Obviously it depends on the individual system, but for the most part I’d say computers still running IDE drives are really too old to be in general use, other than for specialized linux systems. Even the PCs I drag out of the local dump have SATA drives nowadays (uhh, not that I do that often or anything, but .. you know.. ummm. yeh…)

Anyway, I’m not saying computers with an IDE hard drive are useless, but the article was already getting long enough! Perhaps it’s time for a fresh “what to do with an old (IDE hard drive based) PC” article?

James Bruce

Just to clarify, I meant if the computer ONLY had IDE connections. My gaming PC has an IDE cd-drive, but 10x SATA connections for h/d. Obviously, that isnt outdated. But in general, if your computer doesn’t even have SATA (which was created 10 years ago, by the way), then it probably isnt much good to run win7…


Title of article should probably reflect that this is more for your standard desktop mid or full tower PC. Mac Pro users just need to open the side, remove an empty disk tray, attach the sata hdd to the tray, put back in and format for example.

In contrast to your dated IDE statement; Considering the age and interface, IDE users would likely find them selves in more need of a how to article like this than current SATA users ;)

Brad Jobs

That is pretty darn good step by step guide to install a second physical hard drive. This is very useful for noobs that does not have a clue on computers.

James Bruce

Thanks Brad, thats what I was aiming for. It’s difficult to cover everyone’s needs every time.

James Bruce

Good point nizbot – the title should be more appropriate. I did actually put SATA in there originally, but it was perhaps edited out to appeal to a larger audience who are not familiar with the terms SATA and PATA/IDE.

I dont agree about users with SATA not needing this article though – it was aimed at quite low level users for whom opening their pc case is perhaps something they’ve never considered before.

I was planning to include IDE drives in the article originally too, but then it just got far too long, and I think honestly I’m correct in standing by my statement that if your computer only has IDE interface, it’s now more than 10 years old and really ought to be replaced. Unless you plan on using it as a linux media server or something, in which case you are probably at the level at which changing a hard drive is something you do for fun.


Very good article,please write one on IDE also just for sake of our thirst for knowledge.


I second this. Great article. Thank you.



Most of the information given is the same as here. The only thing to be aware of is that the power supply and cables are different. (as pictured in the article) They will only go in one way though as the power plug is shaped and the ribbon plug has a notch on one side which goes into the corresponding slot on the drive. You have the option of either changing the jumper (small black clip) on the back to make the drive a slave (secondary) (use small tweezers to remove and replace according to the picture on the drive) or use the cable. Most ribbon cables have 2 attachments – your main drive should be attached to the master attachment. Most drives are supplied with the jumper set to cable select – this means that the position of the drive (master or secondary) is dependent on which connector you use. The middle connector if I remember correctly is the slave and the end is the master. If you are copying stuff to a new drive then you can use and one of them is a Seagate you can use Seagate’s own disc wizard free