The solution is very simple to disable the Spell Checker e.g. Auto-Correct in Windows 8.1 or Windows 10!
Please use the Keyboard-Shortcut [Windows-Logo]+[C] and click Settings! (... see Image-1 Arrow-1)
In settings please click Change PC settings in Windows 8.1/10! (... see Image-2 Arrow-1)
In PC settings please click or tap the text PC and devices in Windows 8.1 / 10!
And now change the Settings for Spelling and Auto-Correction (... see Image-4 Arrow-1 and 2)
FAQ 226: Updated on: September 24th 2018 23:58