Hit the "Del" key every second or so as the machine is booting up. From there you can use the arrow keys to navigate your BIOS and see if it detects a hard drive. While you're there, find the boot device order and if there is a hdd, make sure it's set to boot from it.
More than likely whoever sold it wasn't going to leave there OS and files on it, so they formatted the drive. You'll need to install an OS.
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