Cumulative updates KB4103721 can brick your Windows 10 computers
Users may experience a few issues after applying the cumulative updates - KB4103721 - for version 1803 for Windows 10 computers. On applying, the screen turns black and the system doesn't boot. This is due to an unidentified bug, which Microsoft has not addressed and is believed to be working upon.
The only possible workaround is to downgrade or uninstall the latest cumulative update KB4103721 or restore a previous point. Restoring to a previous point in time won't affect your personal files and data. It can help you get rid of all apps, drivers, updates that were instated after the restoration point.
Here are some simple steps:
1. Hit F11 as soon as computer powers on.
2. Find the "Advanced Startup Options" menu
3. Click "Go to the previous build"
If this doesn't work, try "System Restore". If a previous restore point is not available, you've to get into "Safe Boot mode" to manually remove the update.
Boot into Advanced Startup, follow these steps:
1. Select Troubleshoot -> Advanced options -> Startup settings -> Restart
2. Click F5 for Safe Mode with Networking and log into safe mode
3. Go to Settings > Update & Security > Windows Update > View update history > Uninstall updates
4. Select and remove KB4103721
5. Now you can reboot your computer, it should boot without trouble once the update has been uninstalled.
You can also clean install Windows 10 April 2018 update using a bootable USB stick.