Windows 10 keeps adding another keyboard layout [duplicate]
Please try the following instructions.
Control Panel > Language
If 'English (United States)' is not a visible option then re-add it by clicking 'Add a language'
Once added click 'options' on the US language and add an input language.
Add the pt-br input method.
Remove the United States input method.
Go back to 'Change your language preferences' and remove the English (United States) language you had added.
Hope this helps! good luck. (: