I encountered this error multiple times now:
- I downloaded the Media Creation Tool from here
- I used the tool to download Windows 10 (happened to me with 1803, 1809 and 19H1)
- Plug it in the new PC and start the setup
The error occurs during the Windows installation. While it is extracting the files I get "Windows cannot install the required files. Make sure all files required for installation are available, and restart the installation. Error code: 0x80070022". I tried different thumbdrives, redownloading Windows 10, changing USB ports (...) but nothing stops this error for me.