Check this post for more information.
It contains Intel CPU microcode update to reduce the impact of Spectre vulnerabilities.
However, it caused a lot of trouble to Windows users.

Or performance problems occur when playing music, using Chrome or other applications.
After installing the patch Ive already have five systems that have been rendered unbootable.
Most of them are Xeon E5 v4 based workstations.

Be careful if this update shows up.
Its been giving me a headache since this morning.
From the looks of it on Google Im not alone with this problem.
Its quite hard to get rid of it too.
So far Ive not been succesful in recovering a machine without redeploying Windows and blocking the update.
The above Reddit post also provides a method to delete this update.
You just need to use the Windows Recovery Environment on a system that cannot be started.
Lets have a look at his solution.
I just succeeded in repairing one workstation that couldnt boot anymore into Windows.
Users with AMD processors are also offered Intel microcode update, so AMD users are not excluded.
Before you try the following fixes, youd betterbackup data without booting Windowsin case of accidental data loss.
Fix 1.
Insert the bootable USB or CD/DVD on your setup and change BIOS boot order to boot from it.
Choose your language preference, and move on.
Go toTroubleshoot>Advanced options>Startup Repairto perform Startup Repair.
If the startup is unable to help you and it’s possible for you to try the next method.
Fix 2.
At this time, you canrepair damaged MBRby taking the following steps.
Go toTroubleshoot>Advanced options>Command Promptto pop pop the command prompt window.
Input the following commands one by one and pressEnterkey after each of them.
Inputexitto kill the command prompt window and reboot your Windows 10.
Here are detailed steps.
And this will not delete any personal file.