Got an important reminder now during update season: Your backups beat ANY other form of security. There is nothing better than just going back to what you remember was working and running smoothly.
1. Before you update to Fall Creators Update 1709, make sure to backup all partitions on the system drive, especially System Reserved partition and that tiny insignificant looking 16 MB partition. Also, don't delete any partitions Microsoft creates. It will free up a little bit of space, but if Windows cannot find that little 16MB Microsoft Reserved Partition, it refuses to update your OS. Just little lessons I learned. Keep them all. They don't use up more than 500-900 MB of space anyway. Make that full system backup before you upgrade. I found myself reverting back to 1703 multiple times before my upgrade to 1709 succeeded. I don't know what I would have done without it. Probably would have put a fork in it and do a clean install losing everything.
2. From my experience, Windows update just leaves me with a slow and buggy OS. You get the best results doing an in-place upgrade by downloading the ISO, extracting it and clicking on setup.exe. Instructions here. Follow the instructions religiously, disable group policies that block the installation of drivers/programs, and disable ALL security software. You would think it doesn't run during the install process... nope. Windows is still running in the background and your antivirus will scan every file installed and block unknown files corrupting your upgrade.
Repair Install Windows 10 with an In-place Upgrade