that means the bios its not finding the hardrive with the OS in it, to be able to do that you would need to acces the bios by hitting f2, or esc, or f1 or whatever key your computer tells you to press to acces the bios, once inside your bios, you need to verify that your computer its recognisin your hard drive, in order for me to help you further you will need to tell me what your bios options are, but most of them are simple , you just need to read carefully, you can also check your boot order in your bios, it need to be cd rom first (if you plan to install an OS) otherwise ill sugest setting that up to hard drive first.
But the firs part ill check would be any sata or ide loose cables.....
good luck.