How to install a secondary Serial AT Attachment hard drive to your existing desktop computer you are asking yourself?. If both your hard drives are Serial AT Attachment type desktop computer hard drives, then what you will need to do is use a Serial AT Attachment cable numbered “1” for your primary hard drive. Then you will want to use a second Serial AT Attachment cable numbered “2” for your older secondary hard drive.
Serial AT Attachment cables are marked with numbers to make installing multiple hard drives and or optical drives to your desktop computer easier. You can try to boot your desktop computer up with both your hard drives configured this way and it should work by successfully posting. If that computer does not boot or boots off the wrong hard drive, then you can go into the computer’s Basic Input Output System and make sure your boot order is correct.
Your new one and a half terabyte Serial AT Attachment hard drive should be listed first with your older hard drive listed second. You can read this adding a hard drive Hewlett Packard web page that shows you how to add an additional hard drive to your Hewlett Packard desktop computer system, so that you have both hard drives configured and installed correctly. If all goes will this will allow you to boot off your new one and a half terabyte hard drive and be able to access some data off your old secondary hard drive.
If you want to become able to switch back and forth and boot off each hard drive then that will require more diligence and is beyond the scope of this article. Basically, you would want to access your computer's boot order before that computer attempts to boot off the first hard drive. These instructions were written for a Hewlett Packard Media Center M7250N desktop personal computer with a new secondary one and a half terabyte hard drive, but can certainly be used as basis points for adding a secondary Serial AT Attachment hard drive into other desktop personal computers.