I could go to the Quicken folder in Documents, right click on the Q file, and just do a file rename. My concern is whether there is something in the Quicken program that looks for the file names as originally setup and won't recognize the renamed file.

So make a copy of the original file under the new name and see if Quicken will open it.

And if that works, rename the original file to a third name and see if Quicken will still open the new-name file.

Then if THAT works, do a couple backups of the new-name file and then you can delete the third-name file.