i had to do this on an hp. its F11 right when you start it. in will bring up a restore page. and select which one you want. My hd had a partion so i reinstalled from that and it took about an hour and a half. I f you have a restore cd/dvd use that. You could also call dell(probly no help at all but try if you want) to walk you through it. Or refer to any booklets that came with it to give you exact details for a full system restore.