audiowindows 7windows-vista
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.
This is often caused by Windows thinking (often incorrectly) you are running an application that uses a microphone/telephony, and lowers other sounds for you.
Try the following to disable this behavior:
In the Start menu, search in the Settings category (Win+W)for "Change Sound Card Settings".
In the Communications tab, change "When Windows detects communications activity" to Do nothing.
The problem appears to be with the Realtek audio driver's Dolby Digital Plus component, which is enabled by default. This thing seems to boost audio volume (and I guess is used for other things such as surround) when it is turned on, but appears to have a bug that turns it off whenever any application starts using the microphone (in non exclusive mode) and turns back on when the microphone is released by all applications. I'm not sure the exact condition for this issue (my first search seems to only reveal issues for Acer and Lenovo laptops and it may be related to hardware configuration), but this means that you will notices a difference in volume between when the microphone is in use and when it is not.
This discussion seems to summarize the issue http://community.acer.com/t5/2014-Archives/Dolby-Home-Theatre-v4-keeps-turning-off-by-itself/m-p/101213#U101213
You can turn it back on once an application using the microphone starts and everything seems to work fine. As long as the microphone is constantly in use by any application it seems to remain on. But close all applications then start another one that uses the microphone, and it will turn itself off again.
I can't seem to find any solution to this besides constantly checking and keeping it on. But do you need this feature? You can simply manually turn off Dolby Digital Plus resulting in permanently lowered, but stable volume. Then you can adjust your system volume to your liking knowing it will not change.
I hope this will be helpful information. It still seems to be a relevant bug 1 years later...
Best Answer
Windows 7 does persist the audio settings for applications in the registry:
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.exeand deleting it fixed the problem.