Windows 8 Pro cannot boot - Error 0xC000021a

Where can I find the "force drivers to have signature disabled"  I cannot find it in the Aptio Setup Utility

Best solution out so far(if you had preserved your copy, even better) upgrade to Windows 10.

This solution is still valid! It worked for me. Thanks Yuri.

Hi

Can you boot into Safe Mode?

I've dealt with this problem twice on the same laptop already. one was on 8 and another time with 8.1.

if you have the simplest version of this problem Amir's solution will work, if not then you probably hve the nasty kind that's HELLA HARD to find n get rid of.

plan on working in CMD for awhile. forums leading you to other fourm after forum. The problem is one of the security updates from microsoft and usually it will show after an auto-update.

here's a shortcut. open up CMD as an administrator.:::: (I couldn't use the "online" command so change it to whatever your hard drive is on usually :C:\ write everything down as it says so you dont screw up a line. start deleteing your current updates. I would do them all!! then run some test after like SFC /scannow and any others and try restarting in safe mode. it worked for me but be ready to ease her back to life. if you get to the desktop make backups or copy files or whatever you have to and restart.

Works on Windows Server 2008R2, 7, 8 and higher

1. Find the list of packages installed on the machine with the issue by performing this command

Code:

dism /online /get-packages /format:table

2. From the list get the Package Identity Name

Code:

Package_for_KB2870699~31bf3856ad364e35~amd64~~6.2.1.1

3. Run this command to uninstall the update silently

Code:

DISM.exe /Online /Remove-Package /PackageName:Package_for_KB2870699~31bf3856ad364e35~amd64~~6.2.1.1 /quiet /norestart

google images of what you should be seeing