cmd as admin (can’t use this method with powershell…)
C:\Windows\system32>assoc /? Displays or modifies file extension associations ASSOC [.ext[=[fileType]]] .ext Specifies the file extension to associate the file type with fileType Specifies the file type to associate with the file extension Type ASSOC without parameters to display the current file associations. If ASSOC is invoked with just a file extension, it displays the current file association for that file extension. Specify nothing for the file type and the command will delete the association for the file extension.
Examples:
assoc .rar=7zip assoc .rar=