Hi,
I have older AMD Athlon 64 X2 6000+, Asus MB, after installation of KB4056892 the system doesn't boot, it only shows the Windows logo without animation and nothing more. After several failed boots it do roll-back then it shows error 0x800f0845. Unfortunately, it seems it's not easy to disable the automatic updates without gpedit tweaks, so it tries installing and rolling-back the update over and over. The sfc /scannow shows no problem, in-place upgrade also doesn't seem to help. I can try full reinstall, but I doubt it will change anything. It seems like the update is binary incompatible with my old CPU. I understand that making the machine unbootable is the best protection from remote exploitation, but I would rather have the OS working. Especially if my CPU is not vulnerable to the Meltdown attack and the MS mitigation attempts for Spectre is more than questionable. I could find only some German and Italian people reporting the same issue (well the CPU is quite pre-historic and the KB update is very fresh), but no info / acknowledgment from the MS so far. I have Czech localization. Could anybody provide more information?