You could try clicking Start/Control panel/adminesterative tools/ click computer management and click on the disk management. There you can check the other hard drive and tell windows to use it. It may be that windows needs to set the drive up for use.
Right click on "Disk 1" then look to the toolbar, click on action and choose "Rescan" this will scan the drive and it will now show in my computer. This is for a drive that has info. on it that you want to keep.
If you don't want to keep the info. then choose format from the right click. j.