I am attempting to use ASIO4ALL with Power Tracks for Windows, but unfortunately the Windows 10 task bar "left/right volume slider" in this case, does not work. The volume seems to be stuck on LOUD, and the Windows 10 task bar volume control will not work to vary the volume. Hope someone has seen this.

Have you looked at the Windows Sound options in your Control Panel to make sure the correct device is what you expect?

Hello rharv,
Thank You for your response.
I did go to control panel/sound and verify that my default sound device is RealTek High Definition Audio speakers.
This Windows 10 Velocity Micro PC comes with a drivers disk, so I used that, to verify that this machine has the manufacturers recommended RealTek HD sound drivers.
This machines "Normal" Windows 10 sound system appears to be working OK - that is, iTunes and Windows media player for audio. The problem comes when I attempt to use asio4all (version 2_14) with any other program such as Power Tracks Windows 2019 (with the build 2 update). I believe there is superposed to be some sort of software link from the Windows 10 taskbar horizontal left/right volume slider to the sound path coming from the asio4all system. That software link appears to be broken, and so far, I have not been able to discover the problem.
Thank you, in advance, for any thoughts you or any others may have in finding the "Missing Link".

Does the Powertracks Master volume work as expected?
You may have to use that while working in PT or RB.

Yes the PG music apps master level controls are still working, and this is helpful for PTW and RB - not so much for Pro Tools.
I tried an msconfig bare bones startup, as well as Microsoft scannow, - those things did not help, and of course I've re-installed my Audio Drivers, asio4all, and PTW - Those things have not helped. I've loaded an early C Drive disk image from a time when there were no music programs yet installed on this PC and just installed PTW as a test, but surprisingly - this did not help. I'm beginning to suspect that this anomaly may be buried in the internals of this particular machine's operating system. If none of our helpers has mastered this particular bug before, what is left may be the "nuclear "option.
Thanks for your thoughts so far.