Sound theme in Windows 7 isn't correct

Recently I feel something very strange and I realize the sound theme I usually use isn't correct. That's Garden theme.
The reason I say it isn't correct because when I choose the Nature theme, I still hear its sound theme (Garden) exactly the same as Windows default. The rest themes still works.
I go to to folder C:\Windows\Media to check for the Garden folder, it's still there.
I have used SFC but it didn't work. Watch the video, listen very carefully when I click to Nature theme and switch to Default theme. The sound they play is one
[REPORT ISSUE] Garden sound theme doesn't work - YouTube

How can I do to fix it? Thanks

question in MS community: Sound theme in Windows 7 isn't correct - Microsoft Community

torchwood said:

Hi Ntd,
You have to set the defaults for Each theme you use.
So in the screenshot
Select the view THEN change the defaults >> desktop >> Colour >> sounds >> screensaver.

Roy

It seems what you say is not for my case. You can see in the video that all the themes is default, the sound theme named "Garden" in Nature theme - one of default themes. This sound theme has the sound exactly the same as the default sound when you choose the Default theme (blue screen with windows flag). That means Garden sound theme doesn't connect to its exact audio files. You can go to folder: C:\Windows\Media to listen for the true Nature sound theme. Please listen carefully the sound when I change theme. Each theme has different style, except Nature

Oh it seems no one has any idea about it
Now I can say that it's definitely incorrect