Microsoft has recently released a cumulative update, titled KB4103721 Version 1803, which was aimed at fixing a number of bugs discovered in the Windows 10 April 2018 Update, but it looks like it is also causing problems of its own for some PCs.
A thread on Microsoft’s Community support forum features a number of people who have had trouble turning on their PCs and booting into Windows 10 after installing the patch, and instead being faced with a black screen.
At the moment, Microsoft has not acknowledged the issue, and we’re chasing for a comment. It should be noted that while some people are experiencing this issue, many others are not. However, if you are concerned about this, you shouldn't install the KB4103721 Version 1803 update just yet.
How to fix it
If you've installed the update and are experiencing the issue, then you’ll need to fix some files that appear to have been corrupted. To do this, you’ll need to enter Safe Mode, which will require booting Windows 10 from a USB drive.
Once the ISO file is downloaded, it can be burnt to a DVD or put on a bootable USB stick.
To make a bootable USB drive use Microsoft’s Windows USB/DVD Download Tool on another PC.
Then, insert the USB drive into the unresponsive PC and boot from there (usually done via going through BIOS, by pressing the ‘Del’ key on your keyboard when your PC turns on).
Once the USB stick loads the Windows 10 setup wizard, click ‘Next’, then select ‘Repair your computer’. Then go to Troubleshoot > Advanced options > Command Prompt.
When the Command Prompt appears type in:
Press 'Enter' then close the Command Prompt window, and click ‘Continue’. Windows 10 should now boot into Safe Mode.
The member of the Community forums who found the bug also posted a video on how to fix it (see below), and they suggest in Safe mode you open up the Command Prompt and type in the following commands:
You could also try:
Now, in the search bar in the Windows taskbar, type ‘System Configuration’. Click the ‘Boot’ tab, then uncheck ‘Safe Boot’ and click ‘Apply’. This will stop your PC from always booting into Safe Mode.
Once you restart your PC, it should load Windows 10 correctly. Hopefully Microsoft will release a much more straightforward fix for this issue soon.