The evil that lies in RAVCpl64
For the last two years, I have been baffled and bamboozled by the audio driver going bad in the tiny Gigabyte PC I use in my entertainment room.
My initial fix was to reinstall the driver, repeatedly, something that took a good ten minutes each time. The fix lasted a few weeks, then a few days, and finally for only a day.
The computer has two audio drivers. Intel's audio driver worked over HDMI; the one from RealTek did not. But the Intel one would disappear, leaving only the RealTek. Ergo, no sound.
Naturally, I searched forums to solve the problem. It is not uncommon. After trying a dozen different things, a comment from one frustrated user struck a chord with me: he noted the problem occurred when the computer lay idle. I realized that that matched my experience.
The question then became, What was happening when the computer was idle (running, but not being used by me). For some reason, some thing was removing the Intel sound driver during the time of passivity.
My hunt changed to looking for what might be doing the dastardly deed -- was it Windows, or was it something else making the "correction" to my system?
One day last week, I was using CCleaner to peruse settings on the computer. I noticed that RealTek loaded an audio utility program during start-up, called RAVCpl64.exe. I usually try to minimize the number of programs being loaded during boot up, and so I turned it off from loading. As I did, I thought --- hmmm, I wonder if this is the culprit.
I monitored that computer for a week, rebooting it from time to time, letting it sit idle for hours on end. The Intel driver hung in there.
Solved: Prevent RAVCpl64.exe from auto-loading during boot-up.