Try this maybe? i know sims CC comes in either .package or .script files, so depending on if both of those file types are associated with notepad, you may have to repeat steps 3 and 4 for both extension types.
1:
Search "File Explorer Options" in windows search bar. Hit enter.
go to the view tab, look under advanced settings - Make sure that the option "Hide File extensions for known types" is unchecked.
if not, uncheck it and click "apply".
Close the window.
2:
Go to your desktop and create a new text document, but change the name so it says "New Text Document.xyz" Make sure to change the " .txt" extension to " .xyz"
The computer will ask you if you're sure you want to do this, saying "changing a file extension may cause it to become unstable" ignore that warning, and click "yes".
(this will confuse your computer, as .xyz is not a real extension and no programs use it, this will display it as an inaccessible file.)
3:
now go to your Sims mod folder, right-click one of the mods and select "Open with". make sure the "Always use this app to open" box is checked.
Your only options should be: Notepad, or search for another app in windows store, and then to search for other apps on this PC to open the file.
Scroll all the way to the bottom and select "Choose another app on this PC" - this will open an explorer window.
4:
In the File Explorer window just opened:
Find Desktop on the sidebar (where you saved the "New Text Document.xyz" file.)
at the bottom of the explorer window, just above the open and cancel buttons is a dropdown menu that should be set to "Programs" - you're gonna click that and change it to "All files"
now select your New Text Document.xyz file
(since this is not a program, the computer will not be able to successfully open, and no association will be made)
Your computer will give you a warning, saying "This program cannot be run on this PC" or something to that extent. Ignore that, close it.
5:
windows will not associate your CC files with any program whatsoever, setting it back to the blank state it was in by default.
You can delete the New Text Document.xyz file now, it's completely useless.
I'm sure there's a way in Windows Registry to do this, but this worked for me.
Hope this helps!
