Escalating priveleges or permissions to allow cfg changes

I was forced to reload FSX on a new W11 computer. When I try to change some dialog in Notepad in order to install an add-on, it says access denied. I figured this out years ago but for the life of me I can't seem to remeber what I did. Even Google has been no help, offering way too complicating things involving coding and other bizarre stuff. I know it isn't difficult because I did before but my aging brain needs some help. Please...