A Vodenstag computer question (USB Boot Drive)

Oh, boy. My Dell Win 10 Pro desktop suffered a MS Update last night, and won't reboot. None of the Dell repair / restore options have worked so far: I'm holding off on a complete "recovery" which would involve repartitioning the boot SSD & losing all the data on it, then reinstalling the OS, etc. Luckily, all my documents, images, etc., are saved to another HD, but, I would lose the programs on the boot drive and have to reinstall them, which means losing lots of settings and so on. So far as I can tell, I may be able...