The time to change the jumper pin settings on both drives is before they are installed in the drive bays of the computer case. For this example, we will make the new drive the "slave" drive. This allows you to copy your operating system and other files over to the new drive using software such as ©Norton Ghost, etc.
If jumper pins are not set correctly, your system could lockup at boot, or your system may not recognize one or more of the hard drives.
To change the jumper settings on your drives, you will need your hard drive manuals to figure out the correct jumper pin settings. Sometimes this information is displayed on the back of the drive. If you are unsure of the settings, visit your hard drive manufacturer's web site.
Remove your current C: drive from its computer case and change its jumper pin setting from "standalone" or "single" to "master" or "master with slave". Change the jumper pin setting on your new (second) drive from its factory "master" setting to "slave".

The next step is to attach the hard drive ribbon cable. The ribbon cable must be correctly attached to each drive and the motherboard with "pin 1" always being closest to the stripe on the IDE ribbon cable . "Pin 1" is also placed closest to the power connector.

Notice the bright red or blue line on the edge of the ribbon cable. This represents the first pin connection, pin 1, on the drive. The ribbon cable must connect to pin 1 on the motherboard and pin 1 on the master and slave drives in the same manner. Pin 1 is marked on the motherboard as well as on all hard drives. If the cable is not connected correctly to each drive and the motherboard, your system will lockup at boot. This is usually evidenced by a hard disk light that continuously remains on with no evidence that the drive is being read. Sometimes you will also get a DOS message asking you to insert a boot disk.
Carefully insert your drives into the computer case and attach the power connectors to each drive. Use only the proper screws to mount the drives! Screws that are either too long or too large can permanently damage your drive. Also, do not over-tighten the mounting screws. Check all cables and connectors on and around the drives to make sure you didn't pull any cables loose when you inserted the drives.

Now you are ready to power on your computer. Put your Windows Startup disk and/or Installation CD in the proper drive . Power up your system and press the delete key during the DOS memory check to access your computers BIOS settings. Select the hard disk detection menu item. You should see your current C: drive settings under the primary hard drive master. Write these down on a piece of paper for safe keeping and do not change them. Go on to the configuration of the primary hard drive slave. Your BIOS should auto detect your new hard drive and give you its settings. If the BIOS correctly detects your drive it should report the drives capacity correctly. If it does not detect your drive, you will have to manually enter the correct settings for your drive which includes the number of cylinders, heads, and sector of your drive. Write down these settings and save them in case your BIOS is ever corrupted. Once your hard drive is configured, exit the hard drive configuration are and select the main BIOS configuration menu item. Make sure your BIOS is configured to boot off of the A: drive or the CD-ROM drive first (before your primary hard drive). Save your BIOS settings (press the F10 key and type "Y") and the computer will reboot.

You drive will now boot off of the disk in the A: drive or the CD in the CD-ROM drive.
Those using the Win 95/98 Startup disk will have to use the FDisk and Format commands to partition and format the new drive. Read about Partitioning and Formatting HERE.
Should you partition a drive? If you use Windows 98 there are no performance reasons that require partitioning of a drive. On the other hand, if you have any thoughts of running a second OS on your computer, it would probably be a good idea to make at least one partition. Those using DOS or Windows 95 prior to release B, should partition their drives in 4 GB or less increments. This is because these OSs could not control cluster sizes. Should the new drive be the C: drive? Since your newer drive is probably faster and/or larger than your current drive you should probably copy over the operating system from your current C: drive if you have the software to do it. This will save you the long process of installing Win95/98 on your new drive. (If you want to keep your current drive as the C: drive, do not copy the operating system to the new drive.)
On the other hand, if Windows or Internet Explorer is running slow and your disk is cluttered up with old drivers and unused files, you might want to skip that option and do a fresh install of Windows on the new drive.
Note: If you want to do a fresh install of Windows to the new drive then there is no need to set the new drive up as the slave. Configure the new drive as the "master" and the old drive as the slave.
Either of these choices will require you to change the jumper settings (new drive is "master with slave" and the old drive is the "slave") and to change your BIOS settings again.

• If you're just adding the second drive for extra file storage, all you will need to do is to partition and format it.
• If you're installing the second drive for a secondary operating system, you'll need to partition and format it also. It's easier to do this in DOS first, then the operating system that you're installing will be able to identify it. A non-Windows operating system or an NTFS file system will have to reformat the drive, however.
  

Once you've made the choice of which drive is the C: and which is the slave and, if necessary, you have copied the OS to the C: drive you are ready to boot Windows and to make sure you drives are working correctly. If your new drive is the slave, you won't have to copy any files.
Remove any disks from the A: and boot your computer. Your computer should now boot into Windows. If your computer never makes it to the Windows boot screen, turn off your computer, and make sure all cables are securely connected and that jumper pin settings are correct. After Windows has booted, click on MyComputer and you should see icons for your drives and any partitions you created. If you right click on a drive or partition and select properties you will see the size of the partition or drive reported in bytes and gigabytes (GB). Copy a few files to your new drive, if you haven't done so already, to make sure everything works. Secure the hard drives to the computer case and put the top of your case back on.
You're Done!