Hello,
Sorry to hear you are having issues.
Open Sound Packager app click on edit sounds and scroll through both
Windows and File Explorer sounds and then change and save the any one you want too.
You'll need Wav sound files to replace your sounds not MP3 ..
You'll also find that some sounds in Windows are not available to change or won't change ,
just play around to see what can be done ..
See Images below



AzDude
Stardock Community Assistant