The taskhost.exe is using 100% of the CPU power and when it's process is ended from the Task Manager nothing bad happens, the PC is still running fine. What triggers this supposedly legit file/process and leaves it behind exhausting the PC resources for nothing? Any ideas?
Thanks a lot for the hint.
For those who are still struggling with this issue here are instructions for a remedy:
Go to the Task Scheduler (may be found under Administrative Tools from the Programs Menu)
Find the entry Task Scheduler Library/Microsoft/Windows/RAC and delete the task in the right pane.
In my case it was repeatedly triggered every hour and kept my CPU at 100%.
This will not actually remove the taskhost.exe but it will eliminate unnecessary Reliability Analysis Task process which is keeping the CPU at maximum rate.