Dell bios how to reinstall the system

1, boot: F12 point and click a few times until the BIOS appears. 2, click on the "BIOS SETUP"; 3, select: the left side: "Update Recovery" ;4, look at the right side: BIOS Recovery from Hard Drive" (from the hard drive to reply to the BIOS), in the - sentence: "When Disabled is selected, BIOS firmwareupdate procedure does not store the recovery file on the user primary hard drive. BIOS Recoveryis only vailable via theexternal USB key using on- demand process." (When Disabled is selected, BIOS firmwareupdate procedure does not store the recovery file on the user primary hard drive. BIOS Recoveryis only vailable via via external USB key using on-demand process. Operation: Close the following button (gray). 5, click on the application change: "APPLYCHANGES" , prompt box ask you whether to save the settings? Select on, click OK. 6, exit: select: "EXIT" shutdown. 7, boot F12, click to enter the BIOS, see your USB flash drive, click it, is the USB flash drive boot. You can directly install the system or enter the PE system.