Error Code 0x80070422 Windows 10 Update Solutions
How does this Error Code 0x80070422 in Windows pop up?
This .NET Framework 3.5 for Windows 8 or Windows 8.1 won't come with pre-installed .Windows 8, Windows 8.1 or Windows 10, and must be separately enabled to run applications that depend on it. So enable the .NET Framework 3.5 in Control Panel to avoid Error code 0x80070422 .

Note: Make sure you have set correct Date and time on your computer, try to install pending updates through other available networks. Run windows update troubleshooter.

First go to Control Panel> Programs and Features.
Turn Windows features on or off then check .NET framework 3.5 . The pre-requisites should installed.
If it is not successful uninstall the KB's related to .NET framework 3.5 and then re-install them.
At last, restart your computer if needed
If the windows update error code 0x80070422 still exists, follow some more steps to fix the issue and install/upgrade/update your operating system.

You Can Try These Solutions To Fix Error Code 0x80070422 Windows Update While Updating/Upgrading:-
Perform a SFC scan so that you can fix potentially corrupted or missing files, most of cases this system file scan fix common issues with file system.
To do a restore to healthy previous setup with command prompt to fix potentially corrupted or missing files
Using windows update troubleshooter fix it tool , this is also a good tool to automatically fix most common issues.
By cleaning SDF (Software distribution folder) for a clean slate for Windows Update or renaming so machine itself creates a fresh one in next update.
Resetting PC

Simple SFC Scan Method for Common File System Issues to Fix Windows Update Error:-
System file scanning process is very simple to try while fixing issues with windows issues. Just follow these steps .

Type CMD in windows start menu search and right click on CMD application to get through Run as admin option.
In the command prompt window, type SFC/SCANNOW and press enter.
The scanning process takes some time to return results.