What is your goal here?
Do you want to replace the original drive? In other words move your Operating System to the new drive and then leave the old one out?
If so you need to "clone" (disk image) your old hard drive (assuming Dell will let you).
I see no options (quick glance) from WDC to clone drives.
http://support.wdc.com/download/index.asp?cxml=n
If WDC does not have a "clone" option you will have to reinstall your Operating System assuming that you want to remove your old hard drive.
Also there are third party softwares you can purchase to do this running @ 80$ US.
If you just want the new drives for storage that is a different and easy thing to do. Just plug them in and format.