I had to replace my motherboard on my Dell Studio XPS 1645. After I replaced it, I downloaded the latest BIOS from Dell (A13) but it failed and give me the following error message: "BIOS update failed! Image verification failed. Error code -200" Now the computer will only occasionally boot up properly. It will book up if the computer was recently on. But if left off for more than 12 hours, the boot up will freeze and there will be a blank screen. I will then have to force a shut down and turn it back on and boot into safe mode. Then I do a restart and it will boot properly. I have a feeling the BIOS wasn't flashed properly. How can I fix this?