In simple terms - When you first connect a new drive either internally or via an external drive port you will need to tell your computer its OK to use it.
Step by step (For Windows PC's Only):
- Right Mouse Click on the "My Computer" icon
- Select "Manage" - this is only possible if you are an administrator
- From the main panel on the right - double click on "Storage"
- Chances are you only have one option - so go ahead and double click on "Disk Management"
Now you should see any existing drives plus the new drive (that you have already attached, but as yet has not responded or appeared in My Computer).
- Select the new drive and activate it as a Primary Partition - but BE CAREFUL - make no changes to your existing drives.
That should be it now and when you close all the windows you have open, you should be able to see your new drive when you open Windows Explorer.