原來也有人有這種問題歐~~~
試試看把下面的存成reg
匯入後，到控制台去改一下，應該就可以了~~~

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\AppEvents\EventLabels\.Default]
@="預設音效"

[HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default]

[HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default\.current]
@="DING.WAV"

[HKEY_CURRENT_USER\AppEvents\Schemes\Apps\.Default\.Default\.Default]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
00,5c,00,6d,00,65,00,64,00,69,00,61,00,5c,00,64,00,69,00,6e,00,67,00,2e,00,\
77,00,61,00,76,00,00,00