Had To Restore My PC

Hello, I had to restore my pc because it crashed after I tried installing the windows SP3. The first timne I started the computer after the restore, I turned on my External Hard Drive, (WD My Book Essential 2TB, Model WDBACW0020HBK-NESN) and got the message for found new hardware but i don’t know where my installation cd is so I just clicked on cancel. The WD Unlocker was still on MY Computer and was able to use the Hard Drive for 2 days. Just today I was trying to use it again but this time the FOund New Hardware message did not show up and it is not in my computer either. The SmartWare icon is still on the taskbar on the bottom right of the screen but I cant open it or anything. Is there a way to install the same software i had before if I don’t know where my disc is?

The my book doesn’t have any installation CD, check if your my book is still recognized on the disk management window. 

http://wdc.custhelp.com/app/answers/detail/a_id/1284