Desktop Operating Systems and Recovery

For years, I used this desktop as my main machine with absolutely no problems listening to audio tracks, either via the onboard sound connected to powered speakers or via a USB DAC connected to a headphone amp. I used a variety of audio software, but have always used Foobar2000 for critical listening. I never, ever had problems with pops, clicks, or dropouts until upgrading to 20H2, whether listening to music or viewing clips on YouTube or programming via Hulu or Netflix.

I can't play any audio only material via Foobar or GrooveMusic without numerous pops/clicks/dropouts now, nor can I play YouTube videos in Chrome or watch anything on Hulu or Netflix without those issues. This problem occurs with any USB DAC, running via DirectSound, WASAPI, or ASIO output in Foobar, or with the onboard sound.

Several pro audio forums suggested downloading and running LatencyMon, and the culprit appears to be storport.sys. Every minute or less, LatencyMon shows storport.sys to have a DPC routine execution time of more than 10,000 microseconds, which flags the system as unsuitable for real-time audio playback.

Actions taken: Installed all the optional Intel device updates via Windows Update. Updated all audio drivers. Rolled back video driver. Disconnected all USB devices and Ethernet cable, booted up Win10 and started LatencyMon without any other apps running in foreground...no improvements whatsoever.

I posted these issues to Audio Science Review forum, and within an hour, several audiophiles replied, stating they also discovered these same problems across a broad variety of hardware after upgrading to 20H2. Some have solved them by updating specific USB drivers, but that's not possible for the Z220. I also have a 400G1 mini that was just updated to 20H2. It  has minimal software loaded as I intended to use it as a tiny music server for my large speaker rig4, and it now has the same problems with high storport.sys latency--and now there are pops/clicks/dropouts using the onboard sound or two different USB DACs.

How can one determine what particular app or service is responsible for problems with storport.sys latency? It appears to have been a problem for various folks ever since the introduction of Win10. Thanks in advance for any input.