In case you're reaching out because of this problem on your laptop, please try performing a Hard Reset: 1. Disconnect any external devices including the AC adapter (and battery if possible) 2. Hold the power button down for 20~30 seconds  3. Bypass any power strips, surge protectors or battery backups  4. Verify the wall outlet is functional  5. Plug only the AC adapter/battery back into the laptop  6. Attempt to power on the system and finish the update. If that does not solved the issue, proceed to the next step. 1. Remove the AC adaptor and wait for the battery to drain completely (it can take minutes or hours depending on the battery level). 2. After the battery drained completely, connect the AC adapter back and press the Power button for 25 to 40 seconds until the battery charging LED blinks twice and then the release power button.  3. Once that is done, check if the update was complete and you have the new BIOS installed.   
My new Optiplex has been stuck with the Dell logo against a black screen at 0% for 12 hours. Please  HELP
Firmware update stuck at 0%