I have been using Audacity for years and it is great but with my Win 7 computer I can NOT lower the input when I have the recording set to "stereo mix".
I use stereo mix setting to record music off of YT.
Adjusting the 3 sliders in the photo below does nothing to lower the INPUT signal, it still pegs out in the red most of the time.
There are NO settings in my computer except "line input" which I can set to 10% and it will still peg out.
See photo:

Hi, Bill, have you tried opening Windows volume control? It has both recording and playback settings.

First make sure you have downloaded the version for windows 7. If your running at 64 bit make sure you have the 64 bit version installed.

You can also try this:
You should be able to adjust the input settings by clicking on your speaker icon in the lower right corner of your task bar. Then click on mixer (#1). You should then be able to adjust your input settings by adjusting the levels (#2).

Hi guys, Steve I have Audacity V 1.2.6 I don't know if it is for 64 bit or not.
I have a 64 bit computer.
Which slider do I adjust, the "system sound" or the "speaker sound" sliders?
The syetem sound slider is set at 90%, the line input is set to 50%.

I'm on a Mac, but I have to adjust input volume on the computer before it gets to Audacity. If the signal through the computer hardware is to high it can't be corrected in software.

Thanks guys, I think I fixed it.
When Audacity is "open" and when I click on the speaker icon like others have mentioned and than click on
"mixer"at that point there is a slider showing for "Audaacity" I lowered it from 100% down to 45% and all seem to be working great now.
THANKS again guys I appreciate all the help.