Your USB has to be formatted FAT32, not NTFS. If the only file on the FAT32 USB is the BIOS update .exe file. All you have to do is tab to the Start button. Then confirm info in top left box has correct current BIOS info and top right box has new BIOS info. Assuming it's all correct, click the Start button. Leave PC alone while it's working. It may reboot ~3-4 times. Even if it looks like it has shut down completely, just leave it alone until you're back at the desktop.
Hello, I am having a similar issue installing the most recent bios. Attempting to install from windows, I'm getting the same error as everyone else (Error : Driver Version Fail) - as i have had with previous bios update. Anyway, I tried installing from flash drive using the BIOS update utility and it will not find my flash drive. Some Details: XPS8930_1.1.26.exe is the only file on the flash drive. I reformatted the drive before copying the file over with a standard NTFS. I unplugged all devices but a keyboard and the flash drive. I shut completely down, and started from power off. (even unplugged the power cord and pushed the power button once to really clear it out) What happens: When i get into the bios update utility the only source it shows is FSO:, the folder in there is EFI, which contains Microsoft, DELL and one other folder, i don't recall its name. But this is not the Flash drive. I have tried tabbing to the source drop down menu to see if i could switch from FSO to USB or whatever it would be but when i hit the space bar or enter on the drop down, nothing happens, which indicates to me that it is not finding the usb drive? I'm not sure what else I can do here? Is there something set wrong in the BIOS that is preventing me from doing this? I'm pretty sure the settings are 99%+ defaults, i may have changed one or two things over the years but nothing that comes to mind. What else can i try?
BIOS 1.1.26, Driver Version Fail and BIOS update utility doesn't find flash 
drive