Hey there moonos21
You may have to activate the hard drive first in Disk management.
To do this click Start > Run and type
diskmgmt.msc and click OK.
The Disk Management snap-in will open
There should be an unallocated drive underneath your C:\ DRIVE, if you are unsure then post a screenshot for us to view.
You should be able to right click on it and either enable or allocate the drive space.
Once it is enabled you can format it and copy information to it.
More help can be found on the microsoft site:
http://support.microsoft.com/?kbid=309000