These are new HDD's in the antistat package from the OEM. If you have not installed HDD's please talk with someone who has before purchasing. You will need to find the HDD in your hardware settings (operating system dependent)and formaton your computer before they will work.There is not an operating system installed on these HDD's and will not boot up automatically. If a HDD doesn't work, I will refund or replace it for you. I will make it right for you.