I have a Satellite C70-A-170 and I updated the BIOS from V1.50 to 1.60 under Windows because the DVD drive was not displayed in the boot menu before. Now I have the new BIOS on it, but I can not adjust there. No button reacts. A BIOS downgrade is denied me. Does anyone have any advice / advice on how I can overwrite the new BIOS again? Helmut