Updating to Windows 10, version 1903 still fails after required Intel RST update
Solution 1:
Installing the latest Intel RST driver seems not to work. After clicking on the Refresh button the Installation Assistant still indicates that there is an old Intel RST driver installed. Rebooting the Computer also does not help.
I was sure I have installed the latest driver so I stopped the Windows Update Service (Windows-Logo-Key + R; services.msc; Enter;). While the service is stopped I have deleted the SoftwareDistribution-Folder (C:\windows\softwaredistribution). Then I started the Windows Update service again. Windows will download the 1903 Upgrade again and there won't be any errors anymore while installing the new OS.
Solution 2:
You have forced the installation before Microsoft decided to include your computer in the upgrade process. I would advice to wait for Microsoft to ask you to install it.
If you still want to force it:
Download the full version of the update from Microsoft at Download Windows 10 as an ISO file.
Boot in Safe mode, then double-click the ISO and execute the setup program to install Windows 10 version 1903.
Before starting, ensure you have good backups for your personal data. If possible, take a backup image of the entire disk and ensure that you can restore it. Forcing the update this way is risky.