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I had the same problem earlier, but there is a solution. Download the BIOS from the dell website and put it on a flash drive. From the flash drive, click on the bios and run it while windows is still on (do not turn off computer). When this happens, the bios will attempt to update but never really shows any signs of it other than creating a folder on a flash drive that has a text file called log. Open this text file and see where a file is trying to be executed, and go to the location of that file. Extract that file (it should still be compressed) and then try clicking on the bios and running it from the flash drive again. Now, a pop up with broken graphics emerges and asks if you if you want to update. Say yes, and then it works. Don't get scared of the broken graphics on the pop-up, the update worked for me. The only weird thing is that the laptop dell update programs still think the bios hasn't updated, except everything else can see that the bios has now updated to 1.9.0.
Please reply if my method worked or not for you all.