Almost Same Problem. Updated BIOS and the computer would not reboot. Bios beep claimed no memory RAM. Rest system by unplugging and removing back-up battery. Was told this was a way to reset cmos . Problems solved computer booted and just had to set Time and Date. Later read there is also a CLR CMOS Jumper "http://www.fixya.com/support/p349329-dell_dimension_4700_47007yxkp61_pc/manual-14426/page-102" For More Info.