cas123

Like icecool33 say check bios but dont format if you are able see the hdd there, download the seagate tool -> http://www.seagate.com/ww/v/inde ... M100000dd04090aRCRD and run the advance test. It might be able to fix the error without formating

If you dont see the hdd in bios, try change sata cable, sata power plug, different port or in to a different computer.