I had been getting intermittent Blue Screens of Death, "A problem has been detected and Windows has been shut down...." Stop code 0x00008086. I called Dell technical support and the tech. took control of my computer and made changes in several areas of the computer including the registry. Then she said she was going to updated the BIOS. Then it read "BIOS update successful and she rebooted. My question is should I do a complete backup of my computer or would a differential backup be sufficient?