After installation of KB4056892 boot failure, after roll-back error 0x800f0845

Crap, I have this issue too with an older AMD HP. After the update it does not even get as far as the login screen but freezes on the windows bootup splash screen, no HDD activity nothing.

Rolling back works but it installs with the same issue again! Should I just add this buggy update to an exeption not to install or is there a fix? Will it recieve updates afterwards automatically or are they dependent on this update? I lose access to the computer this evening and only have a short while to troubleshoot in the evening :(

Block the update or disable updates if that is not possible.   The update is suppose to be a security against a cpu level virus that disables your system.  If then a virus by definition causes harm to your system then this update is a virus released by MS that causes your system to be disabled.   And it was done knowing that the manufacturer has not made changes so that means they did this intentionally to cause harm.

At last got this update installed and believe or not but the computer is much usable with the new build. The meltdown patch doesn't seem to slow it down but actually resolves some hiccups I had with it before. The disk IO response time is much better.

Maybe this is ultimate fix for lot of computers new and old which feeled slow(SSD or not) even if benchmarks doesn't show any bottlenecks.

edit: After KB4058258 update can't search for new updates got error 0x800705b4. Disabling windows defender for moment fixed this issue.

You have to install a "small" 600Mb update after it rolls back from failed update - https://support.microsoft.com/en-en/help/4073290/unbootable-state-for-amd-devices-in-windows-10-version-1709

Just start the computer and power it off 3times when windows logo shows up and before it reboots itself and it should recover.

NO they have not. I can attest to the fact that my computer is stuck in a continuous boot loop that never ends, no matter what you do. Tell me, will you be paying us back for the WEEKS we spent getting NO HELP by Microsoft ? Or maybe because you read a few things you think we have all been helped. Because this thing is pages and pages long and gets longer every single day. More and more people angry with machines that aren't usable anymore due to negligence. Maybe Microsoft should reach out to us, apologize for the weeks of anguish visited upon us by them. This is a PR nightmare and instead of making it good, they stay silent, or maybe as their mouth piece, you can let them know. We are thousands strong, thousands that are already looking to other systems like Linux. As you can read I am one of many who are growing more and more angry by the day, so maybe think about that before you come on here and pretend to have a fix. Either HELP or get off this thread. 

While it may be frustrating for all of us, what are you trying to achieve by ranting here?  Do you seriously think Microsoft will be reimbursing ANY of us for our time?  

We don't get paid by Microsoft for contributing to this forum, and posting suggestions here is not on the condition it resolves your problem, it is best efforts only. 

If you have read the suggestions and they don't work for you,  then include all the relevant details of the process you followed, there may still be somebody on the forum willing to assist.

you just need to install KB4058258 and the problem will be fixed.