I am running a W.D. 20 gig hard drive and just bought an aditional 120 gig W.D. drive. They are bothe 7200 rpm ide drives. My question is, do I need to install an operating system in the second drive in order for it to work. I have them bothe connected to the same ribbon and windows lists the new drive in device manager and claims that it it working properly, but their is no letter assigned to it. When I click on volume for that drive it doesn't list anything.