Open the start menu with the windows logo, search up disk management.
If it shows up there it will be in black with "unallocated space" just right click and pick new simple volume and follow that menu screen.
If it doesn't show up there then insure that you have plugged into the hard drive a sata cable for data which goes from the hard drive to the motherboard and also ensure that the power connector from the powersupply is connected.