Symptoms: No more system sounds on Vista. No more Flash sounds. I still had sound under Windows Media Player.

Cause: I used a tool called "Vista Manager" to clean my registry. Since my system was taking sometimes minutes to shutdown. Cleaning the registry it appears this tool also removes entries that are important to the sound system,

Adding the following registry entry back restored sound on my system:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32]

"wavemapper"="msacm32.drv"

I hope this saves someone hours (yea hours maybe even days!) to figure this out. It looks like many have experienced sound problems in Vista.