These days storage space has become an issue in our daily life, it is no longer
documents alone that cover lest space, we now store video, audio, images and all other sorts of data that take a lot space. So let’s look how we can add more space in our computer.

Before we start the process of adding a drive, we need to do a small amount of research inside your machine. The goal of the research is to find out if it will be easy or not so easy to add the new hard drive. We also need to find out what kind of drive you need to buy. You may be able to do this research by reading through your computer's manuals, but it is far easier to simply open the case and look inside, since most of these machines are assembled.
Find out what type of cable system is used to connect drives to the motherboard. There are two systems in common use: IDE drives (also known as PATA, or Parallel ATA), and SATA (Serial ATA) drives. PATA drives have wide, flat cables or thick cables as wide as your finger, while SATA drives have thin cables about the diameter of a pencil. You will need to know whether to buy an IDE or SATA drive, and you should be able to tell by looking at the cables.
Now that you have confirmed that there is space to install a new drive in your machine and you know what type of drive you need (PATA or SATA), you can buy a new drive.
You can buy a new hard drive from many different places: a retail store, a large computer store, a local computer parts store or by mail order. Wherever you go to buy it buy it, keep three things in mind:
Before we start working with the drive, we need to talk about static electricity. Your computer is highly sensitive to static shocks. This means that if you build up static electricity on your body and a shock passes from your body to something like a hard drive, that hard drive is dead and you will have to buy another one. ¬
The way to eliminate static electricity is by grounding yourself. There are lots of ways to do this, but probably the easiest way is to wear a grounding bracelet on your wrist. Then you connect the bracelet to something grounded (like a copper pipe or the center screw on a wall outlet's face plate). By connecting yourself to ground, you eliminate the possibility of static shock. You can get a bracelet for a few dollars.
First, set the jumpers (if it is an IDE drive). Let's talk about this in more detail, because most people have IDE drives.
In the IDE system, most motherboards allow you to have two IDE cables. Each cable can connect to two drives. Usually you use one cable to connect one or two optical drives to your machine. The other cable is used to connect one or two hard drives to your machine.
You want both hard drives to be on the same cable. The two drives on the cable are called "master" and "slave." You want your existing hard drive (which contains the operating system and all of your current data) to be the "master" and the new hard drive to be the "slave." The drive should have instructions on them that tell you how to set the jumpers for master and slave. So read the instructions and set the jumpers. If you are using SATA drives, you do not need to set jumpers for master and slave because each drive gets its own cable.
Now that the jumpers are set correctly, mount the new drive in your drive cage and screw it into place. 
Next, plug in the drive's power connector to the power supply. If it fits, then it's a match.
Connect the IDE or SATA cable to the drive.
Close the machine, power it up and configure your new drive using the Windows XP drive administration tool. To do this, click the Start button, open the Control Panel, Switch to Classic View, click on Administrative Tools, click on Computer Management, click on Disk Management.
Look at the graphical area in the bottom right of this display. Disk 0 is your original hard drive. Disk 1 is the new hard drive. Chances are that the new drive will not be initialized, or formatted. Click the small button to initialize the drive, and then format it as an NTFS volume (right click on the new drive, then click “Format...”). Formatting may take an hour or more, so be patient.
When the formatting is done, you are ready to use your new drive.