Thank you, JohnBC. You put me on the right track. Although, I could have worded it a bit better by saying the slider would not ding any more when moved. The Ding.wav file was not missing from the Media folder.
Even though your method of using the "ding.reg" file would work, it would have put the "Musica Default.WAV" in there; not Ding.wav. I prefer to work on the Registry manually, so I opened it up in Regedit.exe and put this in:
HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default]
HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default\.Default
In Data, I typed this in:
C:\WINDOWS\media\Ding.wav
HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default\.Current
In Data, I typed this in:
C:\WINDOWS\media\Ding.wav
Restarted Windows and it works fine now.
BTW, un-installing and re-installing Multimedia Sound Schemes in Windows Setup will not fix this problem.
I just found out via another forum that un-installing Norton AntVirus will remove those keys from the registry, and I did that a week ago.