Volume randomly turning itself down on Windows 7 64-bit

This is the weirdest issue I've ever encountered with my PC. Every so often, my sound will start playing back at a lower volume. This happens when watching video, listening to music, all independently.

It usually lasts anywhere up to a minute, after which it will turn up again.

The weird thing about it is that the volume control in Windows remains at 100%, even though the volume is audibly a lot lower. (No, I'm not going deaf, it's just my PC. I checked.)

I just have no idea where to go to troubleshoot this, even.

I'm using Windows 7 64-bit with an on-board Realtek sound-card.

Oh, just in case someone finds this question on Google or whatever, making sure this is on Do Nothing may fix your problem. Unfortunately, it did not work for me.

My settings all seem fine. This is my audio slider. (Took the screenshot while the issue showed.)

I would check for a bad connection or splitting cable to your headphones or speakers. I've had this happen to me before.

Try bending your audio cables in different directions at both your PC's end and the audio equipment's end.

It could be a Steam setting that lowers your system volume when you get a message.

Turn it off in your Steam settings.

I had a similar problem on an HP s2300z slimline system, except the audio was seemingly stuck in the "turned down" mode and then occasionally would double in volume, if only briefly.

For posterity, the details:

• Asus M2N61-AR
• GeForce 6150SE nForce 430 Chipset
• Realtek ALC888S Audio Chipset
• Running Realtek driver dated 8/4/2009, version 6.0.1.5910

Symptoms: Audio playback would sometimes be normal and then jump to loud (seemingly twice as loud) briefly during playback, sometimes for just a moment and then sometimes for as long as 10 seconds Seemed to correlate in some way with CPU load My volume meters had to be up to 100% for the OS, and 100% for the media playback software, with my speaker volume knob at about 1/3 level in order to get "normal" playback volume.

Resolution: I went to Realtek's site and downloaded version 2.7 of their audio drivers. Those drivers did a clean uninstall of the existing drivers, rebooted, and then finished installing the new ones, rebooting again afterward.

I haven't had audio issues since.

Hope this works for someone else!