Precision 5520 with bios 1.23.1 will not update. I have tried reinstalling 1.23.1 and tried installing 1.24 and 1.25.  The "preparing" screen shows up and the crawl bar completes, then the system reboots and nothing happens.  The bios just remains at 1.23.1.  I have also tried running each one from a flash drive, with the same failure.  Have shut down every possible running program and run every boot attempt as Administrator, with no luck.

Anyone have a way to get these bios updates to complete?