If you open My Computer, do you see C:, D:, and maybe E: if you have a disc reader?
What I think is going on is that you have not initialized, partitioned and formatted the second HDD.
Right Click on My Computer, goto Manage
In the Computer Management Console that just appeared, goto Disk Management.
You should be auto prompted to initialize the disk. Basically keep hitting next until finished
this youtube vid is not bad if you have any serious probshttp://www.youtube.com/watch?v=_rqn5ubXo18