To preempt the inevitable MS expert response, Yes I have tried a clean boot and no a virus scan did not pick up anything. Also I have installed all current updates and security patches.
So, now we've got that out of the way we can get on to how to resolve this known serious issue with the Windows 10 operating system.
I a program installs itselft without your permission, exhibits behaviour that renders a system virtually unusable and resists attempts to disable or uninstall it you'd call it a virus, right?
Windows Compatability Telemetry (CompatTelRunner.exe) starts automatically, consumes 100% of disk resources for long periods, runs at higher priority than user tasks and resists all attempts to disable it. So I'm calling it what it is - A virus.
I've tried disabling it in the scheduler, disabling related services, setting registry keys to stop it starting but it always finds a way to start running again.
If this were a well behaved critical system function that kind of resilience might be acceptable but it is not. It is spyware installed by Microsoft to monitor usage in order to improve their product.
Well here's an improvement suggestion - Don't install irremovable utilities that render the system useless for long periods and annoy your customers.
If Microsoft do not remove this virus, I am going to have to resort to writing a service that runs in the background killing it every time it starts up. I would rather not waste my time doing that because I'm sure MS will find a way to make it even more unkillable so I'll have to waste even more time finding a way round that, and nauseum.
I know there is no guarantee that anybody in MS who can actually do anything will actually read this but I have to try.