@bradb922, check to see which version of Windows originally came with that computer. There is a certificate of authenticity with a Product Key on the bottom of the laptop if it is Windows 7.
If it originally came with Windows 8, there may be no sticker. If this is the case, your life is easier.
Go to Microsoft's website and download their media creation tool. It is available for Windows 7, 8.1, and 10, but Windows 7 you need to enter a key. Use this utility to download and create a bootable USB. If the hard drive is correctly installed, the USB will be able to format and install Windows on to that hard drive.