Windows 10: How do I undo "always open with ______"

So I accidentally made it that I open .json files with paint.net but that doesn't support .json files, how do i change it so i dont always open .json files with paint.net?

:)

 

How to undo "always open with" option in Windows 10 (1803 build)

I accidentally click "always open with" a particular application on a BibTeX file and now the icons of all such files change to the icon of that app and I cannot find a way to undo the operation. In fact, I want Windows to always ask me how to open
a BibTeX file instead of sticking to a specific program. Thanks for any suggestions!

Here I found some related posts but none of them seem to solve my problem:

• How do I undo "Always open with" option in Windows 10
• How to undo "Always open with" option in Windows 10

Here are what I've tried, but none of them works:

• Execute "assoc .bib= && assoc .bibtex=" in cmd.exe as Administrator.
  Nothing happens.
• In Settings under "choose default apps by file type", remove the default app at ".bib" entry.
  However, there's no such entry.

 

Mail app will not open on 10041.

Hello Adam,

This is the suggested solution below if you haven't already tried it.

In this Windows 10 build 10041, the Mail, Calendar, and People apps may be broken due to a licensing issue with the Store Beta. To get these apps working again, you need to follow these steps:

• Open powershell as administrator
• Run the command Get-appxprovisionedpackage –online | where-object {$_.packagename –like “*windowscommunicationsapps*”} | remove-appxprovisionedpackage –online
• Re-install Mail, People and Calendar from the Store (green tile)

 

Undo option in File Explorer

Hi Helena,

We appreciate your time and effort for getting back to us.

Try the following steps and check if it helps:

• 
  Press Windows + E keys from the Keyboard to open the
  File Explorer.
  
• 
  Click on the drop down of Customize Quick Access Toolbar beside
  File Explorer.
  
• 
  Click on Undo.
  

Kindly let us know if you need any further assistance with Windows. We are glad to assist you.

Thank you.