Well is it detecting the drive? It should have a little pop up in the bottom right corner saying "Found new hardware" if it isn't doing that, you're going to need to pop in the CD and find something along the lines of a driver, search through each folder and you'll eventually find something.
If this still isn't working right click on "My Computer" then click on manage then in the list click on Disk Management. If you can see "Extrenal HDD" or something along the lines/similiar to your external HDD name.. Right click on it and go "Format" . If it is there but greyed out, right click on it and select "Initialize".
If this still doesn't work you can go to Control panel, then System then click on the Tab "Hardware" then click on "Device Manager".. A big list should come up .. the top one being "My Computer" and just below it "Disk Drives" .. Press the Squire next to "Disk Drives" with the + on it. It will extend it into a list of Disk Drives installed. If your HDD Isn't there its another tell tale sign that it isn't installed.
If it is there, right click it and go "Uninstall" .. Then Unplug your external HDD, try plugging it back in and see if the PC recognizes it. If it is in the list but has a yellow warning button logo next to the name of your HDD.. It means it hasn't got the right drivers installed for it to work. Right click on the name of your HDD and click on "Update Driver".. It will then have 3 options, Connect to Windows update all the time to get updates, Connect to Windows update once and No, not this time. Click on no, not this time and go next.. Then pop youR CD in and click on "Install the software automatically" then click next and it should start installing drivers for your external HDD.
I hope to jesus any of this works, because this is absolutely all I can think of Divy. Good luck mate