Vista/Win7 appear to persist the sound level settings per application. I'd like to have a look at that list.
The reason? According to a Microsoft blog, the settings are stored against the PID of the application, and I'd really like to find out what that PID is. I'm having trouble isolating which process is 'registering' itself with the Volume Mixer.
Windows 7 does persist the audio settings for applications in the registry:
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\LowRegistry\Audio\PolicyConfig\PropertyStore
There are lots of sub-keys with numeric names. The settings are indexed by full application path so search for the name of your application in there.
I needed to find this because my Media Player Classic suddenly stopped producing any sound, and in a way which I figured couldn't be caused by a mis-configuration on my side. Finding a key containing mplayerc.exe and deleting it fixed the problem.
The PID is the Process ID Number, a semi-random* number assigned to a process when it is created. You can see the process ID of a running process in the Task Manager or pretty much any other program that lists running programs.
The process ID number has no significance outside of being the unique identifier for a given process.
Since PID's don't persist across reboots, etc. I would imagine that the Mixer is storing them in memory.
*Not actually random, but also not generated in any meaningful pattern. Numbers are generally, but not necessarily, assigned in numeric order and in all versions of Windows NT, at least, are multiples of 4.
