: Plug the laptop into a reliable AC power source. Do not rely on battery power during a BIOS update.
If your computer cannot boot into Windows, use a bootable floppy disk or USB drive: Copy the utility file to your bootable media. Insert the media and restart the computer. Dell Portable Bios And Diags Rev A34 120
Rev A34 (often found as file I5150A34.exe ). : Plug the laptop into a reliable AC power source