I know what you are doing wrong. You are getting the error below, correct? That is because you are trying to delete the game that is currently loaded in OOTP. You must either:
- End OOTP and delete the saved game in Windows Explorer, or
- Switch to another game in OOTP, then delete the saved game in Windows Explorer.
By the way, if you do 1., you get an error message the next time you start OOTP because it is still looking for that game. See the second screen print. That's really not a problem; all you have to do is create or load another game.
This is probably confusing the heck out of you. Do this instead. You know how you load a game from the Main Screen? I assume you have more than one; load another game that you want to keep. If not, create another one. Then go back into that Load Game screen. You will now see that if you click on the game that you want to get rid of, the Delete button on the lower left comes on - see the third screen print - use that to delete unwanted games.
Just remember, you cannot delete the current game while the program is running.