Depending on the software you choose, follow the instructions below to clone your old drive onto your new one. Be sure you pick the old drive as the source and the new drive as the target! If you are not sure which drive is which, STOP, do not guess. Turn the computer off and unplug the new drive and then when you power up the computer go into the BIOS and make note of the old hard drive's name. Turn the computer off, plug the new drive back in, and power up the machine back into the BIOS. Make note of the new hard drive's name and then continue on.

We're going to jump ahead briefly and talk about what you need to do once the cloning operation is done. These are important steps, and we want to make certain they are not overlooked; we'll get into the cloning process in just a moment.

Once Finished Cloning, Don't Forget To...

Once the cloning operation is complete, power off your system again and replace the old drive with the new one entirely. It's best to physically remove the original OS hard drive so you don't make any mistakes here. Be sure to set the correct jumper setting on the drive for its new position. This will generally mean you need to set the newly cloned hard drive to the 'master' setting.

Power on the system again, the newly cloned hard drive should be detected automatically during the POST procedure. If it is not, you will need to go into the BIOS to detect it as we've mentioned previously.

Assuming the hard drive is detected, your Windows XP installation should now boot as normal from the newly cloned hard disk. Once you are sure that everything is functioning as it should, you can install your old hard drive as a secondary drive in the system for data storage. Simply follow the steps listed above for installing a second drive.

When you boot into Windows XP your old drive will be present and you can partition and format it as you wish. *I recommend you double check that the cloning operation was fully successful before you go about formatting the old drive however.

Note that it is possible (though unlikely) that Windows XP might require re-activation after this procedure. Don't panic. Simply follow the on-screen steps to contact Microsoft by phone and obtain a reactivation key. This is a fairly painless process.